This chalk consists simply of comminuted corals and shells of the reef. It

has been examined microscopically and found to be destitute of the minute

organisms abounding in the chalk of England. (_Geology of the United States

Exploring Expedition_, p. 150.) Mr. Guppy also found chalk-like coral

limestones containing 95 p.c. of carbonate of lime in the Solomon Islands.

The absence of _Globigerinae_ is a local phenomenon. They are quite absent

in the Arafura Sea, and no _Globigerina_-ooze was found in any of the

enclosed seas of the Pacific, but with these exceptions the _Globigerinae_

"are really found all over the bottom of the ocean." (Murray on Oceanic

Deposits--_Proceedings of Royal Society_, Vol. XXIV., p. 523.)

The above analysis shows a far closer resemblance to chalk than that of the

_Globigerina_-ooze of the Atlantic, four specimens of which given by Sir W.

Thomson (_Voyage of the Challenger_ Vol. II. Appendix, pp. 374-376, Nos. 9,

10, 11 and 12) from the mid-Atlantic, show the following proportions:--

Carbonate of Lime 43.93 to 79.17 per cent.

Carbonate of Magnesia 1.40 to 2.58 ,,

Alumina and Oxide of Iron 6.00? to 32.98 ,,

Silica 4.60 to 11.23 ,,

In addition to the above there is a quantity of insoluble residue

consisting of small particles of sanidine, augite, hornblende, and

magnetite, supposed to be the product of volcanic dust or ashes carried

either in the air or by ocean currents. This volcanic matter amounts to

from 4.60 to 8.33 per cent. of the _Globigerina_-ooze of the mid-Atlantic,

where it seems to be always present; and the small proportion of similar

matter in true chalk is another proof that its origin is different, and

that it was deposited far more rapidly than the oceanic ooze.

The following analysis of chalk by Mr. D. Forbes will show the difference

between the two formations:--

Grey Chalk, White Chalk,

_Folkestone_. _Shoreham_.

Carbonate of Lime 94.09 98.40

Carbonate of Magnesia 0.31 0.08

Alumina and Phosphoric Acid a trace 0.42

Chloride of Sodium 1.29 --

Insoluble debris 3.61 1.10

(From _Quarterly Journal of the Geological Society_, Vol. XXVII.)

The large proportion of carbonate of lime, and the very small quantity of

silica, alumina, and insoluble _debris_, at once distinguish true chalk

from the _Globigerina_-ooze of the deep ocean bed.

[24] Notes on Reticularian Rhizopoda; in _Microscopical Journal_, Vol.

XIX., New Series, p. 84.

[25] _Proceedings of the Royal Society_, Vol. XXIV. p. 532.

[26] See Presidential Address in Sect. D. of British Association at

Plymouth, 1877.

[27] _Geological Magazine_, 1871, p. 426.

[28] In his lecture on _Geographical Evolution_ (which was published after

the greater part of this chapter had been written) Sir Archibald Geikie

expresses views in complete accordance with those here advocated. He

says:--"The next long era, the Cretaceous, was more remarkable for slow

accumulation of rock under the sea than for the formation of new land.

During that time the Atlantic sent its waters across the whole of Europe

and into Asia. But they were probably nowhere more than a few hundred feet

deep over the site of our continent, even at their deepest part. Upon their

bottom there gathered a vast mass of calcareous mud, composed in great part

of foraminifera, corals, echinoderms, and molluscs. Our English chalk,

which ranges across the north of France, Belgium, Denmark, and the north of

Germany, represents a portion of the deposits of that sea-floor." The

weighty authority of the Director-General of the Geological Survey may

perhaps cause some geologists to modify their views as to the deep-sea

origin of chalk, who would have treated any arguments advanced by myself as

not worthy of consideration.

[29] _Introduction and Succession of Vertebrate Life in America_, by

Professor O. C. Marsh. Reprinted from the _Popular Science Monthly_, March,

April, 1878.

[30] _Physical Geography and Geology of Great Britain_, 5th Ed. p. 61.

[31] Of late it has been the custom to quote the so-called "ridge" down the

centre of the Atlantic as indicating an extensive ancient land. Even

Professor Judd at one time adopted this view, speaking of the great belt of

Tertiary volcanoes "which extended through Greenland, Iceland, the Faroe

Islands, the Hebrides, Ireland, Central France, the Iberian Peninsula, the

Azores, Madeira, Canaries, Cape de Verde Islands, Ascension, St. Helena,

and Tristan d'Acunha, and which constituted as shown by the recent

soundings of H.M.S. _Challenger_ a mountain-range, comparable in its

extent, elevation, and volcanic character with the Andes of South America"

(_Geological Mag._ 1874, p. 71). On examining the diagram of the Atlantic

Ocean in the _Challenger Reports_, No. 7, a considerable part of this ridge

is found to be more than 1,900 fathoms deep, while the portion called the

"Connecting Ridge" seems to be due in part to the deposits carried out by

the River Amazon. In the neighbourhood of the Azores, St. Paul's Rocks,

Ascension, and Tristan d'Acunha are considerable areas varying from 1,200

to 1,500 fathoms deep, while the rest of the ridge is usually 1,800 or

1,900 fathoms. The shallower water is no doubt due to volcanic upheaval and

the accumulation of volcanic ejections, and there may be many other deeply

submerged old volcanoes on the ridge; but that it ever formed a chain of

mountains "comparable in elevation with the Andes," there seems not a

particle of evidence to prove. It is however probable that this ridge

indicates the former existence of some considerable Atlantic islands, which

may serve to explain the presence of a few identical genera, and even

species of plants and insects in Africa and South America, while the main

body of the fauna and flora of these two continents remains radically

distinct.

In my _Darwinism_ (pp. 344-5) I have given an additional argument founded

on the comparative height and area of land with the depth and area of

ocean, which seems to me to add considerably to the weight of the evidence

here submitted for the permanence of oceanic and continental areas.

[32] In a review of Mr. T. Mellard Reade's _Chemical Denudation and

Geological Time_, in _Nature_ (Oct. 2nd, 1879), the writer remarks as

follows:--"One of the funny notions of some scientific thinkers meets with

no favour from Mr. Reade, whose geological knowledge is practical as well

as theoretical. They consider that because the older rocks contain nothing

like the present red clays, &c., of the ocean floor, that the oceans have

always been in their present positions. Mr. Reade points out that the first

proposition is not yet proved, and the distribution of animals and plants

and the fact that the bulk of the strata on land are of marine origin are

opposed to the hypothesis." We must leave it to our readers to decide

whether the "notion" developed in this chapter is "funny," or whether such

hasty and superficial arguments as those here quoted from a "practical

geologist" have any value as against the different classes of facts, all

pointing to an opposite conclusion, which have now been briefly laid before

them, supported as they are by the expressed opinion of so weighty an

authority as Sir Archibald Geikie, who, in the lecture already quoted

says:--"From all this evidence we may legitimately conclude that the

present land of the globe, though formed in great measure of marine

formations, has never lain under the deep sea; but that its site must

always have been near land. Even its thick marine limestones are the

deposits of comparatively shallow water."

[33] _Antiquity of Man_, 4th Ed. pp. 340-348.

[34] _The Great Ice Age and its Relation to the Antiquity of Man._ By James

Geikie, F.R.S. (Isbister and Co., 1874.)

[35] This view of the formation of "till" is that adopted, by Dr. Geikie,

and upheld by almost all the Scotch, Swiss, and Scandinavian geologists.

The objection however is made by many eminent English geologists, including

the late Mr. Searles V. Wood, Jun., that mud ground off the rocks cannot

remain beneath the ice, forming sheets of great thickness, because the

glacier cannot at the same time grind down solid rock and yet pass over the

surface of soft mud and loose stones. But this difficulty will disappear if

we consider the numerous fluctuations in the glacier with increasing size,

and the additions it must have been constantly receiving as the ice from

one valley after another joined together, and at last produced an ice-sheet

covering the whole country. The grinding power is the motion and pressure

of the ice, and the pressure will depend on its thickness. Now the points

of maximum thickness must have often changed their positions, and the

result would be that the matter ground out in one place would be forced

into another place where the pressure was less. If there were no lateral

escape for the mud, it would necessarily support the ice over it just as a

water-bed supports the person lying on it; and when there was little

drainage water, and the ice extended, say, twenty miles in every direction

from a given part of a valley where the ice was of less than the average

thickness, the mud would necessarily accumulate at this part simply because

there was no escape for it. Whenever the pressure all round any area was

greater than the pressure on that area, the _debris_ of the surrounding

parts would be forced into it, and would even raise up the ice to give it

room. This is a necessary result of hydrostatic pressure. During this

process the superfluous water would no doubt escape through fissures or

pores of the ice, and would leave the mud and stones in that excessively

compressed and tenacious condition in which the "till" is found. The

unequal thickness and pressure of the ice above referred to would be a

necessary consequence of the inequalities in the valleys, now narrowing

into gorges, now opening out into wide plains, and again narrowed lower

down; and it is just in these openings in the valleys that the "till" is

said to be found, and also in the lowlands where an ice-sheet must have

extended for many miles in every direction. In these lowland valleys the

"till" is both thickest and most wide-spread, and this is what we might

expect. At first, when the glaciers from the mountains pushed out into

these valleys, they would grind out the surface beneath them into hollows,

and the drainage-water would carry away the _debris_. But when they spread

all over the surface from sea to sea, and there was little or no drainage

water compared to the enormous area covered with ice, the great bulk of the

_debris_ must have gathered under the ice wherever the pressure was least,

and the ice would necessarily rise as it accumulated. Some of the mud would

no doubt be forced out along lines of least resistance to the sea, but the

friction of the stone-charged "till" would be so enormous that it would be

impossible for any large part of it to be disposed of in this way.

[36] That the ice-sheet was continuous from Scotland to Ireland is proved

by the glacial phenomena in the Isle of Man, where "till" similar to that

in Scotland abounds, and rocks are found in it which must have come from

Cumberland and Scotland, as well as from the north of Ireland. This would

show that glaciers from each of these districts reached the Isle of Man,

where they met and flowed southwards down the Irish Sea. Ice-marks are

traced over the tops of the mountains which are nearly 2,000 feet high.

(See _A Sketch of the Geology of the Isle of Man_, by John Horne, F.G.S.

_Trans. of the Edin. Geol. Soc._ Vol. II. pt. 3, 1874.)

[37] _The Great Ice Age_, p. 177.

[38] These are named, in descending order, Hessle Boulder Clay, Purple

Boulder Clay, Chalky Boulder Clay, and Lower Boulder Clay--below which is

the Norwich Crag.

[39] "On the Climate of the Post-Glacial Period." _Geological Magazine_,

1872, pp. 158, 160.

[40] _Geological Magazine_, 1876, p. 396.

[41] _Early Man in Britain and his Place in the Tertiary Period_, p. 113.

[42] Heer's _Primaeval World of Switzerland_ Vol. II., pp. 148-168.

[43] Dr. James Geikie in _Geological Magazine_, 1878, p. 77.

[44] This subject is admirably discussed in Professor Asa Gray's Lecture on

"Forest Geography and Archaeology" in the _American Journal of Science and

Arts_, Vol. XVI. 1878.

[45] In a letter to _Nature_ of October 30th, 1879, the Rev. O. Fisher

calls attention to a result arrived at by Pouillet, that the temperature

which the surface of the ground would assume if the sun were extinguished

would be -128deg F. instead of -239deg F. If this corrected amount were

used in our calculations, the January temperature of England during the

glacial epoch would come out 17deg F., and this Mr. Fisher thinks not low

enough to cause any extreme difference from the present climate. In this

opinion, however, I cannot agree with him. On the contrary, it would, I

think, be a relief to the theory were the amounts of decrease of

temperature in winter and increase in summer rendered more moderate, since

according to the usual calculation (which I have adopted) the differences

are unnecessarily great. I cannot therefore think that this modification of

the temperatures, should it be ultimately proved to be correct (which is

altogether denied by Dr. Croll), would be any serious objection to the

adoption of Dr. Croll's theory of the Astronomical and Physical causes of

the Glacial Epoch.

The reason of the theoretical increase of summer heat being greater than

the decrease of winter cold is because we are now nearest the sun in winter

and farthest in summer, whereas we calculate the temperatures of the

glacial epoch for the phase of precession when the _aphelion_ was in

winter. A large part of the increase of temperature would no doubt be used

up in melting ice and evaporating water, so that there would be a much less

increase of sensible heat; while only a portion of the theoretical lowering

of temperature in winter would be actually produced owing to equalising

effect of winds and currents, and the storing up of heat by the earth and

ocean.

[46] Dr. Croll says this "is one of the most widespread and fundamental

errors within the whole range of geological climatology." The temperature

of the snow itself is, he says, one of the main factors. (_Climate and

Cosmology_, p. 85.) But surely the temperature of the snow must depend on

the temperature of the air through which it falls.

[47] In an account of Prof. Nordenskjoeld's recent expedition round the

northern coast of Asia, given in _Nature_, November 20th, 1879, we have the

following passage, fully supporting the statement in the text. "Along the

whole coast, from the White Sea to Behring's Straits, no glacier was seen.

During autumn the Siberian coast is nearly free of ice and snow. There are

no mountains covered all the year round with snow, although some of them

rise to a height of more than 2,000 feet." It must be remembered that the

north coast of Eastern Siberia is in the area of supposed greatest winter

cold on the globe.

[48] Dr. Croll objects to this argument on the ground that Greenland and

the Antarctic continent are probably lowlands or groups of islands.

(_Climate and Cosmology_, Chap. V.)

[49] "On the Glacial Epoch," by James Croll. _Geol. Mag._ July, August,

1874.

[50] "The general absence of recent marks of glacial action in Eastern

Europe is well known; and the series of changes which have been so well

traced and described by Prof. Szabo as occurring in those districts seems

to leave no room for those periodical extensions of 'ice-caps' with which

some authors in this country have amused themselves and their readers. Mr.

Campbell, whose ability to recognise the physical evidence of glaciers will

scarcely be questioned, finds quite the same absence of the proof of

extensive ice-action in North America, westward of the meridian of

Chicago." (Prof. J. W. Judd in _Geol. Mag._ 1876, p. 535.)

The same author notes the diminution of marks of ice-action on going

eastward in the Alps; and the Altai Mountains far in Central Asia show no

signs of having been largely glaciated. West of the Rocky Mountains,

however, in the Sierra Nevada and the coast ranges further north, signs of

extensive old glaciers again appear; all which phenomena are strikingly in

accordance with the theory here advocated, of the absolute dependence of

glaciation on abundant rainfall and elevated snow-condensers and

accumulators.

[51] I have somewhat modified this whole passage in the endeavour to

represent more accurately the difference between the views of Dr. Croll and

Sir Charles Lyell.

[52] For numerous details and illustrations see the paper--"On Ocean

Currents in Relation to the Physical Theory of Secular Changes of

Climate"--in the _Philosophical Magazine_, 1870.

[53] See _Darwin's Naturalist's Voyage Round the World_, 2nd Edition, pp.

244-251.

[54] The influence of geographical changes on climate is now held by many

geologists who oppose what they consider the extravagant hypotheses of Dr.

Croll. Thus, Prof. Dana imputes the glacial epoch chiefly, if not wholly,

to elevation of the land caused by the lateral pressure due to shrinking of

the earth's crust that has caused all other elevations and depressions. He

says: "Now, that elevation of the land over the higher latitudes which

brought on the glacial era is a natural result of the same agency, and a

natural, and almost necessary, counterpart of the coral-island subsidence

which must have been then in progress. The accumulating, folding,

solidification, and crystallisation of rocks attending all the rock-making

and mountain-making through the Palaeozoic, Mesozoic, and Cenozoic eras,

had greatly stiffened the crust in these parts; and hence in after times,

the continental movements resulting from the lateral pressure necessarily

appeared over the more northern portions of the continent, where the

accumulations and other changes had been relatively small. To the

subsidence which followed the elevation the weight of the ice-cap may have

contributed in some small degree. But the great balancing movements of the

crust of the continental and oceanic areas then going forward must have had

a greatly preponderating effect in the oscillating agency of all

time--lateral pressure within the crust." (_American Journal of Science and

Arts_, 3rd Series, Vol. IX. p. 318.)

"In the 2nd edition of his _Manual of Geology_, Professor Dana suggests

elevation of Arctic lands sufficient to exclude the Gulf Stream, as a

source of cold during glacial epochs. This, he thinks, would have made an

epoch of cold at any era of the globe. A deep submergence of Behring's

Strait, letting in the Pacific warm current to the polar area, would have

produced a mild Arctic climate like that of the Miocene period. When the

warm current was shut out from the polar area it would yet reach near to

it, and bring with it that abundant moisture necessary for glaciation."

(_Manual of Geology_, 2nd Edition, pp. 541-755, 756.)

[55] Dana's _Manual of Geology_, 2nd Edition, p. 540.

[56] Dr. Croll says that I here assume an impossible state of things. He

maintains "that the change from the distant sun in winter, and near sun in

summer to the near sun in winter and distant sun in summer, aided by the

change in the physical causes which this would necessarily bring about,

would certainly be sufficient to cause the snow and ice to disappear."

(_Climate and Cosmology_, p. 106.) But I demur to his "necessarily." It is

not the _direct_ effect of the nearer sun in winter that is supposed to

melt the snow and ice, but the "physical causes," such as absence of fogs

and increase of warm equatorial currents. But the near sun in winter acting

on an ice-clad surface would only increase the fogs and snow, while the

currents could only change if a large portion of the ice were first melted,

in which case they would no doubt be modified so as to cause a further

melting of the ice. Dr. Croll says: "The warm and equable conditions of

climate which would then prevail, and the enormous quantity of

intertropical water carried into the Southern Ocean, would soon produce a

melting of the ice." (_Loc. cit._ p. 111.) This seems to me to be assuming

the very point at issue. He has himself shown that the presence of large

quantities of ice prevents "a warm and equable climate" however great may

be the sun-heat; the ice therefore would _not_ be melted, and there would

be no increased flow of intertropical water to the Southern Ocean. The

ocean currents are mainly due to the difference of temperature of the polar

and equatorial areas combined with the peculiar form and position of the

continents, and some one or more of these factors must be altered _before_

the ocean currents towards the north pole can be increased. The only factor

available is the Antarctic ice, and if this were largely increased, the

northward-flowing currents might be so increased as to melt some of the

Arctic ice. But the very same argument applies to both poles. Without some

geographical change the Antarctic ice could not materially diminish during

its winter in _perihelion_, nor increase to any important extent during the

opposite phase. We therefore seem to have no available agency by which to

get rid of the ice over a glaciated hemisphere, _so long as the

geographical conditions remained unchanged and the excentricity continued

high_.

[57] In the _Geological Magazine_, April, 1880, Mr. Searles V. Wood adduces

what he considers to be the "conclusive objection" to Dr. Croll's

excentricity theory, which is, that during the last glacial epoch Europe

and North America were glaciated very much in proportion to their

respective climates now, which are generally admitted to be due to the

distribution of oceanic currents. But Dr. Croll admits his theory "to be

baseless unless there was a complete diversion of the warm ocean currents

from the hemisphere glaciated," in which case there ought to be no

difference in the extent of glaciation in Europe and North America. Whether

or not this is a correct statement of Dr. Croll's theory, the above

objection certainly does not apply to the views here advocated; but as I

also hold the "excentricity theory" in a modified form, it may be as well

to show why it does not apply. In the first place I do not believe that the

Gulf Stream was "completely diverted" during the glacial epoch, but that it

was diminished in force, and (as described at p. 144) _partly_ diverted

southward. A portion of its influence would, however, still remain to cause

a difference between the climates of the two sides of the Atlantic; and to

this must be added two other causes--the far greater penetration of warm

sea-water into the European than into the North American continent, and the

proximity to America of the enormous ice-producing mass of Greenland. We

have thus three distinct causes, all combining to produce a more severe

winter climate on the west than on the east of the Atlantic during the

glacial epoch, and though the first of these--the Gulf Stream--was not

nearly so powerful as it is now, neither is the difference indicated by the

ice-extension in the two countries so great as the present difference of

winter-temperature, which is the essential point to be considered. The

ice-sheet of the United States is usually supposed to have extended about

ten, or, at most, twelve, degrees further south than it did in Western

Europe, whereas we must go twenty degrees further south in the former

country to obtain the same mean winter-temperature we find in the latter,

as may be seen by examining any map of winter isothermals. This difference

very fairly corresponds to the difference of conditions existing during the

glacial epoch and the present time, so far as we are able to estimate them,

and it certainly affords no grounds of objection to the theory by which the

glaciation is here explained.

[58] Dr. Croll objects to this argument, and adduces the case of Greenland

as showing that ice may accumulate far from sea. But the width of Greenland

is small compared with that of the supposed Antarctic ice-cap. (_Climate

and Cosmology_, p. 78.)

[59] The recent extensive glaciation of New Zealand is generally imputed by

the local geologists to a greater elevation of the land; but I cannot help

believing that the high phase of excentricity which caused our own glacial

epoch was at all events an assisting cause. This is rendered more probable

if taken in connection with the following very definite statement of

glacial markings in South Africa. Captain Aylward in his _Transvaal of

To-day_ (p. 171) says:--"It will be interesting to geologists and others to

learn that the entire country, from the summits of the Quathlamba to the

junction of the Vaal and Orange rivers, shows marks of having been swept

over, and that at no very distant period, by vast masses of ice from east

to west. The striations are plainly visible, scarring the older rocks, and

marking the hill-sides--getting lower and lower and less visible as,

descending from the mountains, the kopjies (small hills) stand wider apart;

but wherever the hills narrow towards each other, again showing how the

vast ice-fields were checked, thrown up, and raised against their Eastern

extremities."

This passage is evidently written by a person familiar with the phenomena

of glaciation, and as Captain Aylward's preface is dated from Edinburgh, he

has probably seen similar markings in Scotland. The country described

consists of the most extensive and lofty plateau in South Africa, rising to

a mountain knot with peaks more than 10,000 feet high, thus offering an

appropriate area for the condensation of vapour and the accumulation of

snow. At present, however, the mountains do not reach the snow-line, and

there is no proof that they have been much higher in recent times, since

the coast of Natal is now said to be rising. It is evident that no slight

elevation would now lead to the accumulation of snow and ice in these

mountains, situated as they are between 27deg and 30deg S. Lat.; since the

Andes, which in 32deg S. Lat. reach 23,300 feet high, and in 28deg S. Lat.

20,000, with far more extensive plateaus, produce no ice-fields. We cannot,

therefore, believe that a few thousand feet of additional elevation, even

if it occurred so recently as indicated by the presence of striations,

would have produced the remarkable amount of glaciation above described;

while from the analogy of the northern hemisphere, we may well believe that

it was mainly due to the same high excentricity that led to the glaciation

of Western and Central Europe, and Eastern North America.

These observations confirm those of Mr. G. W. Stow, who, in a paper

published in the _Quarterly Journal of the Geological Society_ (Vol. XXVII.

p. 539), describes similar phenomena in the same mountains, and also mounds

and ridges of unstratified clay packed with angular boulders; while further

south the Stormberg mountains are said to be similarly glaciated, with

immense accumulations of morainic matter in all the valleys. We have here

most of the surface phenomena characteristic of a glaciated country, only a

few degrees south of the tropic; and taken in connection with the

indications of recent glaciation in New Zealand, and those discovered by

Dr. R. von Lendenfeld in the Australian Alps between 6,000 and 7,000 feet

elevation (_Nature_, Vol. XXXII. p. 69), we can hardly doubt the occurrence

of some general and wide-spread cause of glaciation in the southern

hemisphere at a period so recent that the superficial phenomena are almost

as well preserved as in Europe. Other geologists however deny that there

are any distinct indications of glacial action in South Africa; but the

recent discovery by Dr. J. W. Gregory, F.G.S., of the former extension of

glaciers on Mount Kenya 5,000 feet below their present limits, renders

probable the former glaciation of the South African Highlands.

[60] The astronomical facts connected with the motions and appearance of

the planet are taken from a paper by Mr. Edward Carpenter, M.A., in the

_Geological Magazine_ of March, 1877, entitled, "Evidence Afforded by Mars

on the Subject of Glacial Periods," but I arrive at somewhat different

conclusions from those of the writer of the paper.

[61] In an article in _Nature_ of Jan. 1, 1880, the Rev. T. W. Webb states

that in 1877 the pole of Mars (? the south pole) was, according to

Schiaparelli, entirely free of snow. He remarks also on the regular contour

of the supposed snows of Mars as offering a great contrast to ours, and

also the strongly marked dark border which has often been observed. On the

whole Mr. Webb seems to be of opinion that there can be no really close

resemblance between the physical condition of the Earth and Mars, and that

any arguments founded on such supposed similarity are therefore

untrustworthy.

[62] _London, Edinburgh and Dublin Philosophical Magazine_, Vol. XXXVI.,

pp. 144-150 (1868).

[63] _Climate and Time in their Geological Relations_, p. 341.

[64] _Nature_, Vol. XXI., p. 345, "The Interior of Greenland."

[65] Prof. J. W. Judd says: "In the case of the Alps I know of no glacial

phenomena which are not capable of being explained, like those of New

Zealand, by a great extension of the area of the tracts above the snow-line

which would collect more ample supplies for the glaciers protruded into

surrounding plains. And when we survey the grand panoramas of ridges,

pinnacles, and peaks produced for the most part by sub-aerial action, we

may well be prepared to admit that before the intervening ravines and

valleys were excavated, the glaciers shed from the elevated plateaux must

have been of vastly greater magnitude than at present." (Contributions to

the Study of Volcanoes, _Geological Magazine_, 1876, p. 536.) Professor

Judd applies these remarks to the last as well as to previous glacial

periods in the Alps; but surely there has been no such extensive alteration

and lowering of the surface of the country since the erratic blocks were

deposited on the Jura and the great moraines formed in North Italy, as this

theory would imply. We can hardly suppose wide areas to have been lowered

thousands of feet by denudation, and yet have left other adjacent areas

apparently untouched; and it is even very doubtful whether such an

extension of the snow-fields would alone suffice for the effects which were

certainly produced.

[66] _Geological Magazine_, 1876, p. 392.

[67] Colonel Fielden thinks that these trees have all been brought down by

rivers, and have been stranded on shores which have been recently elevated.

See _Trans. of Norfolk Nat. Hist. Soc., Vol. III._, 1880.

[68] _Geological Magazine_, 1876, "Geology of Spitzbergen," p. 267.

[69] The preceding account is mostly derived from Professor Heer's great

work _Flora Fossilis Arctica_.

[70] _Geological Magazine_, 1875, p. 531.

[71] _Geological Magazine_, 1876, p. 266. In his recent work--_Climate and

Cosmology_ (pp. 164, 172)--the late Dr. Croll has appealed to the

imperfection of the geological record as a reply to these arguments; in

this case, as it appears to me, a very unsuccessful one.

[72] It is interesting to observe that the Cretaceous flora of the United

States (that of the Dakota group), indicates a somewhat cooler climate than

that of the following Eocene period. Mr. De Rance (in the geological

appendix to Capt. Sir G. Nares's _Narrative of a Voyage to the Polar Sea_)

remarks as follows: "In the overlying American Eocenes occur types of

plants occurring in the European Miocenes and still living, proving the

truth of Professor Lesquereux's postulate, that the plant types appear in

America a stage in advance of their advent in Europe. These plants point to

a far higher mean temperature than those of the Dakota group, to a dense

atmosphere of vapour, and a luxuriance of ferns and palms." This is very

important as adding further proof to the view that the climates of former

periods are not due to any general refrigeration, but to causes which were

subject to change and alternation in former ages as now.

[73] Mr. S. B. J. Skertchley informs me that he has himself observed thick

Tertiary deposits, consisting of clays and anhydrous gypsum, at Berenice on

the borders of Egypt and Nubia, at a height of about 600 feet above the

sea-level; but these may have been of fresh-water origin.

[74] By referring to our map of the Indian Ocean showing the submarine

banks indicating ancient islands (Chap. XIX.), it will be evident that the

south-east trade-winds--then exceptionally powerful--would cause a vast

body of water to enter the deep Arabian Sea.

[75] In his recently published _Lectures on Physical Geography_, Professor

Haughton calculates, that more than half the solar heat of the torrid zone

is carried to the temperate zones by ocean currents. The Gulf Stream itself

carries one-twelfth of the total amount, but it is probable that a very

small fraction of this quantity of heat reaches the polar seas owing to the

wide area over which the current spreads in the North Atlantic. The

corresponding stream of the Indian Ocean in Miocene times would have been

fully equal to the Gulf Stream in heating power, while, owing to its being

so much more concentrated, a large proportion of its heat may have reached

the polar area. But the Arctic Ocean occupies less than one-tenth of the

area of the tropical seas; so that, whatever proportion of the heat of the

tropical zone was conveyed to it, would, by being concentrated into

one-tenth of the surface, produce an enormously increased effect. Taking

this into consideration, we can hardly doubt that the opening of a

sufficient passage from the Indian Ocean to the Arctic seas would produce

the effects above indicated.

[76] For an account of the resemblances and differences of the mammalia of

the two continents during the Tertiary epoch, see my _Geographical

Distribution of Animals_, Vol. I. pp. 140-156.

[77] Professor Haughton has made an elaborate calculation of the difference

between existing climates and those of Miocene times, for all the places

where a Miocene flora has been discovered, by means of the actual range of

corresponding species and genera of plants. Although this method is open to

the objection that the ranges of plants and animals are not determined by

temperature only, yet the results may be approximately correct, and are

very interesting. The following table which summarizes these results is

taken from his Lectures on Physical Geography (p. 344):--

_______________________________________________________________________

| | | Present | Miocene | |

| |Latitude.|Temperature.|Temperature.|Difference.|

|_____________________|_________|____________|____________|___________|

| 1. Switzerland | 47d.00 | 53d.6 F | 69d.8 F | 16d.2 F |

| 2. Dantzig | 54d.21 | 45d.7 ,, | 62d.6 ,, | 16d.9 ,, |

| 3. Iceland | 65d.30 | 35d.6 ,, | 48d.2 ,, | 12d.6 ,, |

| 4. Mackenzie River | 65d.00 | 19d.4 ,, | 48d.2 ,, | 28d.8 ,, |

| 5. Disco (Greenland)| 70d.00 | 19d.6 ,, | 55d.6 ,, | 36d.0 ,, |

| 6. Spitzbergen | 78d.00 | 16d.5 ,, | 51d.8 ,, | 35d.3 ,, |

| 7. Grinnell Land | 81d.44 | 1d.7 ,, | 42d.3 ,, | 44d.0 ,, |

|_____________________|_________|____________|____________|___________|

It is interesting to note that Iceland, which is now exposed to the full

influence of the Gulf Stream, was only 12deg.6 F. warmer in Miocene times,

while Mackenzie River, now totally removed from its influence was 28deg

warmer. This, as well as, the greater increase of temperature as we go

northward and the polar area becomes more limited, is quite in accordance

with the view of the causes which brought about the Miocene climate which

is here advocated.

[78] The objection has been made, that the long polar night would of itself

be fatal to the existence of such a luxuriant vegetation as we know to have

existed as far as 80deg N. Lat., and that there must have been some

alteration of the position of the pole, or diminution of the obliquity of

the ecliptic, to permit such plants as magnolias and large-leaved maples to

flourish. But there appears to be really no valid grounds for such an

objection. Not only are numbers of Alpine and Arctic evergreens deeply

buried in the snow for many months without injury, but a variety of

tropical and sub-tropical plants are preserved in the hot-houses of St.

Petersburg and other northern cities, which are closely matted during

winter, and are thus exposed to as much darkness as the night of the Arctic

regions. We have besides no proof that any of the Arctic trees or large

shrubs were evergreens, and the darkness would certainly not be prejudical

to deciduous plants. With a suitable temperature there is nothing to

prevent a luxuriant vegetation up to the pole, and the long continued day

is known to be highly favourable to the development of foliage, which in

the same species is larger and better developed in Norway than in the south

of England.

[79] _Geological Magazine_, 1873, p. 320.

[80] _Geological Magazine_, 1877, p. 137.

[81] _Manual of Geology_, 2nd Ed. p. 525. See also letter in _Nature_, Vol.

XXIII. p. 410.

[82] _Nature_, Vol. XVIII. (July, 1878), p. 268.

[83] "On the Comparative Value of certain Geological Ages considered as

items of Geological Time." (_Proceedings of the Royal Society_, 1874, p.

334.)

[84] _Trans. Royal Society of Edinburgh_, Vol. XXIII. p. 161. _Quarterly

Journal of Science_, 1877. (Croll on the "Probable Origin and Age of the

Sun.")

[85] _Philosophical Magazine_, April, 1853.

[86] It has usually been the practice to take the amount of denudation in

the Mississippi valley, or one foot in six thousand years, as a measure of

the rate of denudation in Europe, from an idea apparently of being on the

"safe side," and of not over-estimating the rate of change. But this

appears to me a most unphilosophical mode of proceeding and unworthy of

scientific inquiry. What should we think of astronomers if they always took

the lowest estimates of planetary or stellar distances, instead of the mean

results of observation, "in order to be on the safe side!"? As if error in

one direction were any worse than error in another. Yet this is what

geologists do systematically. Whenever any calculations are made involving

the antiquity of man, it is those that give the _lowest_ results that are

always taken, for no reason apparently except that there was, for so long a

time, a prejudice, both popular and scientific, against the great antiquity

of man; and now that a means has been found of measuring the rate of

denudation, they take the slowest rate instead of the mean rate, apparently

only because there is now a scientific prejudice in favour of extremely

slow geological change. I take the mean of the whole; and as this is almost

exactly the same as the mean of the three great European rivers--the Rhone,

Danube, and Po--I cannot believe that this will not be nearer the truth for

Europe than taking one North American river as the standard.

[87] "On the Height of the Land and the Depth of the Ocean," in the

_Scottish Geographical Magazine_, 1888.

[88] These figures are merely used to give an idea of the rate at which

denudation is actually going on now; but if no elevatory forces were at

work, the rate of denudation would certainly diminish as the mountains were

lowered and the slope of the ground everywhere rendered flatter. This would

follow not only from the diminished power of rain and rivers, but because

the climate would become more uniform, the rainfall probably less, and no

rocky peaks would be left to be fractured and broken up by the action of

frosts. It is certain, however, that no continent has ever remained long

subject to the influences of denudation alone, for, as we have seen in our

sixth chapter, elevation and depression have always been going on in one

part or other of the surface.

[89] The following statement of the depths at which the Palaeozoic

formations have been reached in various localities in and round London was

given by Mr. H. B. Woodward in his address to the Norwich Geological

Society in 1879:--

_Deep Wells through the Tertiary and Cretaceous Formations._

Harwich at 1,022 feet reached Carboniferous Rock.

Kentish Town ,, 1,114 ,, ,, Old Red Sandstone.

Tottenham Court Road ,, 1,064 ,, ,, Devonian.

Blackwall ,, 1,004 ,, ,, Devonian or Old Red Sandstone.

Ware ,, 800 ,, ,, Silurian (Wenlock Shale).

We thus find that over a wide area, extending from London to Ware and

Harwich, the whole of the formations from the Oolite to the Permian are

wanting, the Cretaceous resting on the Carboniferous or older Palaeozoic

rocks; and the same deficiency extends across to Belgium, where the

Tertiary beds are found resting on Carboniferous at a depth of less than

400 feet.

[90] _Geological Magazine_, Vol. VIII., March, 1871.

[91] Mr. C. Lloyd Morgan has well illustrated this point by comparing the

generally tilted-up strata denuded on their edges, to a library in which a

fire had acted on the exposed edges of the books, destroying a great mass

of literature but leaving a portion of each book in its place, which

portion represents the thickness but not the size of the book. (_Geological

Magazine_, 1878, p. 161.)

[92] Professor J. Young thinks it highly probable that--"the Lower

Greensand is contemporaneous with part of the Chalk, so were parts of the

Wealden; nay, even of the Purbeck a portion must have been forming while

the Cretaceous sea was gradually deepening southward and westward." Yet

these deposits are always arranged successively, and their several

thicknesses added together to obtain the total thickness of the formations

of the country. (See Presidential Address, Sect. C. British Association,

1876.)

[93] Mr. John Murray in his more careful estimate makes it about 51-1/2

millions.

[94] As by far the larger portion of the denuded matter of the globe passes

to the sea through comparatively few great rivers, the deposits must often

be confined to very limited areas. Thus the denudation of the vast

Mississippi basin must be almost all deposited in a limited portion of the

Gulf of Mexico, that of the Nile within a small area of the Eastern

Mediterranean, and that of the great rivers of China--the Hoang Ho and

Yang-tse-kiang, in a small portion of the Eastern Sea. Enormous lengths of

coast, like those of Western America and Eastern Africa, receive very

scanty deposits; so that thirty miles in width along the whole of the

coasts of the globe will probably give an area greater than that of the

area of _average_ deposit, and certainly greater than that of _maximum_

deposit, which is the basis on which I have here made my estimates. In the

case of the Mississippi, it is stated by Count Pourtales that along the

plateau between the mouth of the river and the southern extremity of

Florida for two hundred and fifty miles in width the bottom consists of

clay with some sand and but few Rhizopods; but beyond this distance the

soundings brought up either Rhizopod shells alone, or these mixed with

coral sand, Nullipores, and other calcareous organisms (Dana's _Manual of

Geology_, 2nd Ed. p. 671). It is probable, therefore, that a large

proportion of the entire mass of sediment brought down by the Mississippi

is deposited on the limited area above indicated.

Professor Dana further remarks: "Over interior oceanic basins as well as

off a coast in quiet depths, fifteen or twenty fathoms and beyond, the

deposits are mostly of fine silt, fitted for making fine argillaceous

rocks, as shales or slates. When, however, the depth of the ocean falls off

below a hundred fathoms, the deposition of silt in our existing oceans

mostly ceases, unless in the case of a great bank along the border of a

continent."

[95] From the same data Professor Haughton estimates a minimum of 200

million years for the duration of geological time; but he arrives at this

conclusion by supposing the products of denudation to be uniformly spread

over the _whole sea-bottom_ instead of over a narrow belt near the coasts,

a supposition entirely opposed to all the known facts, and which had been

shown by Dr. Croll, five years previously, to be altogether erroneous. (See

_Nature_, Vol. XVIII., p. 268, where Professor Haughton's paper is given as

read before the Royal Society.)

[96] See _Geological Magazine_ for 1877, p. 1.

[97] In his reply to Sir W. Thomson, Professor Huxley _assumed_ one foot in

a thousand years as a not improbable rate of deposition. The above estimate

indicates a far higher rate; and this follows from the well-ascertained

fact, that the area of deposition is many times smaller than the area of

denudation.

[98] Dr. Croll and Sir Archibald Geikie have shown that marine denudation

is very small in amount as compared with sub-aerial, since it acts only

locally on the _edge_ of the land, whereas the latter acts over every foot

of the _surface_. Mr. W. T. Blanford argues that the difference is still

greater in tropical than in temperate latitudes, and arrives at the

conclusion that--"If over British India the effects of marine to those of

fresh-water denudation in removing the rocks of the country be estimated at

1 to 100, I believe that the result of marine action will be greatly

overstated" (_Geology and Zoology of Abyssinia_, p. 158, note). Now, as our

estimate of the rate of sub-aerial denudation cannot pretend to any precise

accuracy, we are justified in neglecting marine denudation altogether,

especially as we have no method of estimating it for the whole earth with

any approach to correctness.

[99] Agassiz appears to have been the first to suggest that the principal

epochs of life extermination were epochs of cold; and Dana thinks that two

at least such epochs may be recognised, at the close of the Palaeozoic and

of the Cretaceous periods--to which we may add the last glacial epoch.

[100] This view was, I believe, first put forth by myself in a paper read

before the Geological Section of the British Association in 1869, and

subsequently in an article in _Nature_, Vol. I. p. 454. It was also stated

by Mr. S. B. J. Skertchley in his _Physical System of the Universe_, p. 363

(1878); but we both founded it on what I now consider the erroneous

doctrine that actual glacial epochs recurred each 10,500 years during

periods of high excentricity.

[101] Explication d'une seconde edition de la _Carte Geologique de la

Terre_ (1875), p. 64.

[102] For most of the facts as to the zoology and botany of these islands,

I am indebted to Mr. Godman's valuable work--_Natural History of the Azores

or Western Islands_, by Frederick Du Cane Godman, F.L.S., F.Z.S., &c.,

London, 1870.

[103] See Chap. V. p. 78.

[104] Some of Mr. Darwin's experiments are very interesting and suggestive.

Ripe hazel-nuts sank immediately, but when dried they floated for ninety

days, and afterwards germinated. An asparagus-plant with ripe berries, when

dried, floated for eighty-five days, and the seeds afterwards germinated.

Out of ninety-four dried plants experimented with, eighteen floated for

more than a month, and some for three months, and their powers of

germination seem never to have been wholly destroyed. Now, as oceanic

currents vary from thirty to sixty miles a day, such plants under the most

favourable conditions might be carried 90 X 60 = 5,400 miles! But even half

of this is ample to enable them to reach any oceanic island, and we must

remember that till completely water-logged they might be driven along at a

much greater rate by the wind. Mr. Darwin calculates the distance by the

average time of flotation to be 924 miles; but in such a case as this we

are entitled to take the extreme cases, because such countless thousands of

plants and seeds must be carried out to sea annually that the extreme cases

in a single experiment with only ninety-four plants, must happen hundreds

or thousands of times and with hundreds or thousands of species, naturally,

and thus afford ample opportunities for successful migration. (See _Origin

of Species_, 6th Edition, p. 325.)

[105] The following remarks, kindly communicated to me by Mr. H. N.

Moseley, naturalist to the _Challenger_, throw much light on the agency of

birds in the distribution of plants:--"Grisebach (_Veg. der Erde_, Vol. II.

p. 496) lays much stress on the wide ranging of the albatross (Diomedea)

across the equator from Cape Horn to the Kurile Islands, and thinks that

the presence of the same plants in Arctic and Antarctic regions may be

accounted for, possibly, by this fact. I was much struck at Marion Island

of the Prince Edward group, by observing that the great albatross breeds in

the midst of a dense, low herbage, and constructs its nest of a mound of

turf and herbage. Some of the indigenous plants, _e.g._ Acaena, have

flower-heads which stick like burrs to feathers, &c., and seem specially

adapted for transposition by birds. Besides the albatrosses, various

species of Procellaria and Puffinus, birds which range over immense

distances may, I think, have played a great part in the distribution of

plants, and especially account, in some measure, for the otherwise

difficult fact (when occurring in the tropics), that widely distant islands

have similar mountain plants. The Procellaria and Puffinus in nesting,

burrow in the ground, as far as I have seen choosing often places where the

vegetation is the thickest. The birds in burrowing get their feathers

covered with vegetable mould, which must include spores, and often seeds.

In high latitudes the birds often burrow near the sea-level, as at Tristan

d'Acunha or Kerguelen's Land, but in the tropics they choose the mountains

for their nesting-place (Finsch and Hartlaub, _Orn. der Viti- und

Tonga-Inseln_, 1867, Einleitung, p. xviii.). Thus, _Puffinus megasi_ nests

at the top of the Korobasa basaga mountain, Viti Levu, fifty miles from the

sea. A Procellaria breeds in like manner in the high mountains of Jamaica,

I believe at 7,000 feet. Peale describes the same habit of _Procellaria

rostrata_ at Tahiti, and I saw the burrows myself amidst a dense growth of

fern, &c., at 4,400 feet elevation in that island. Phaethon has a similar

habit. It nests at the crater of Kilauea, Hawaii, at 4,000 feet elevation,

and also high up in Tahiti. In order to account for the transportation of

the plants, it is not of course necessary that the same species of

Procellaria or Diomedea should now range between the distant points where

the plants occur. The ancestor of the now differing species might have

carried the seeds. The range of the genus is sufficient."

[106] _Nature_, Vol. VI. p. 262, "Recent Observations in the Bermudas," by

Mr. J. Matthew Jones.

[107] "The late Sir C. Wyville Thomson was of opinion that the 'red earth'

which largely forms the soil of Bermuda had an organic origin, as well as

the 'red clay' which the _Challenger_ discovered in all the greater depths

of the ocean basins. He regarded the red earth and red clay as an ash left

behind after the gradual removal of the lime by water charged with carbonic

acid. This ash he regarded as a constituent part of the shells of

Foraminifera, skeletons of Corals, and Molluscs, [_vide_ _Voyage of the

Challenger_, Atlantic, Vol. I. p. 316]. This theory does not seem to be in

any way tenable. Analysis of carefully selected shells of Foraminifera,

Heteropods, and Pteropods, did not show the slightest trace of alumina, and

none has as yet been discovered in coral skeletons. It is most probable

that a large part of the clayey matter found in red clay and the red earth

of Bermuda is derived from the disintegration of pumice, which is

continually found floating on the surface of the sea. [See Murray, "On the

Distribution of Volcanic Debris Over the Floor of the Ocean;" _Proc. Roy.

Soc. Edin._ Vol. IX. pp. 247-261. 1876-1877.] The naturalists of the

_Challenger_ found it among the floating masses of gulf weed, and it is

frequently picked up on the reefs of Bermuda and other coral islands. The

red earth contains a good many fragments of magnetite, augite, felspar, and

glassy fragments, and when a large quantity of the rock of Bermuda is

dissolved away with acid, a small number of fragments are also met with.

These mineral particles most probably came originally from the pumice which

had been cast up on the island for long ages (for it is known that these

minerals are present in pumice), although possibly some of them may have

come from the volcanic rock, which is believed to form the nucleus of the

island." _The Voyage of H.M.S. Challenger_, Narrative of the Cruise, Vol.

I. 1885, pp. 141-142.

[108] Four bats occur rarely, two being N. American, and two West Indian

Species. _The Bermuda Islands_, by Angelo Heilprin, Philadelphia, 1889.

[109] Fourteen species of Spiders were collected by Prof. A. Heilprin, all

American or cosmopolitan species except one, _Lycosa atlantica_, which Dr.

Marx of Washington describes as new and as peculiar to the islands.

(Heilprin's _The Bermudas_, p. 93.)

[110] Mr. Theo. D. A. Cockerell informs me that there are two slugs in

Bermuda of which specimens exist in the British Museum,--_Amalia gagates_

Drap. common in Europe, and _Agriolimax campestris_ of the United States.

Both may therefore have been introduced by human agency. Also _Vaginulus

Morelete var. schivelyae_ which seems to be a variety of a Mexican species;

perhaps imported.

[111] "Notes on the Vegetation of Bermuda," by H. N. Moseley. (_Journal of

the Linnean Society_, Vol. XIV., _Botany_, p. 317.)

[112] _Gigantic Land Tortoises Living and Extinct in the Collection of the

British Museum._ By A. C. L. G. Guenther, F.R.S. 1877.

[113] The following list of the beetles yet known from the Galapagos shows

their scanty proportions and accidental character; the forty species

belonging to thirty-three genera and eighteen families. It is taken from

Mr. Waterhouse's enumeration in the _Proceedings of the Zoological Society_

for 1877 (p. 81), with a few additions collected by the U. S. Fish

Commission Steamer _Albatross_, and published by the U. S. National Museum

in 1889.

CARABIDAE. ELATERIDAE.

Feronia calathoides. Physorhinus galapagoensis

,, insularis. HETEROMERA.

,, galapagoensis. Allecula n. s.

Amblygnathus obscuricornis. Stomion helopoides.

Solenophorus galapagoensis. ,, laevigatum.

Notaphus galapagoensis. Ammophorus obscurus.

DYTISCIDAE. ,, cooksoni.

Eunectes occidentalis. ,, bifoveatus.

Acilius incisus. Pedonoeces galapagoensis.

Copelatus galapagoensis. ,, pubescens.

PALPICORNES. Phaleria manicata.

Tropisternus lateralis. CURCULIONIDAE.

Philhydrus sp. Otiorhynchus cuneiformis.

STAPHYLINIDAE. Anchonus galapagoensis.

Creophilus villosus. LONGICORNIA.

NECROPHAGA. Mallodou sp.

Acribis serrativentris. Eburia amabilis.

Phalacrus darwinii. ANTHRIBIDAE.

Dermestes vulpinus. Ormiscus variegatus.

MALACODERMS. PHYTOPHAGA

Ablechrus darwinii. Diabrotica limbata.

Corynetes rufipes. Docema galapagoensis.

Bostrichus unciniatus. Longitarsus lunatus.

Tetrapriocerca sp. SECURIPALPES.

LAMELLICORNES. Scymuns galapagoensis.

Copris lugubris.

Oryctes galapagoensis.

[114] Mr. H. O. Forbes, who visited these islands in 1878, increased the

number of wild plants to thirty-six, and these belonged to twenty-six

natural orders.

[115] Juan Fernandez is a good example of a small island which, with time

and favourable conditions, has acquired a tolerably rich and highly

peculiar flora and fauna. It is situated in 34deg S. Lat., 400 miles from

the coast of Chile, and so far as facilities for the transport of living

organisms are concerned is by no means in a favourable position, for the

ocean-currents come from the south-west in a direction where there is no

land but the Antarctic continent, and the prevalent winds are also

westerly. No doubt, however, there are occasional storms, and there may

have been intermediate islands, but its chief advantages are its antiquity,

its varied surface, and its favourable soil and climate, offering many

chances for the preservation and increase of whatever plants and animals

have chanced to reach it. The island consists of basalt, greenstone, and

other ancient rocks, and though only about twelve miles long its mountains

are three thousand feet high. Enjoying a moist and temperate climate it is

especially adapted to the growth of ferns, which are very abundant; and as

the spores of these plants are as fine as dust, and very easily carried for

enormous distances by winds, it is not surprising that there are nearly

fifty species on the island, while the remote period when it first received

its vegetation may be indicated by the fact that nearly half the species

are quite peculiar; while of 102 species of flowering plants seventy are

peculiar, and there are ten peculiar genera. The same general character

pervades the fauna. For so small an island it is rich, containing four true

land-birds, about fifty species of insects, and twenty of land-shells.

Almost all these belong to South American genera, and a large proportion

are South American species; but several of the insects, half the birds, and

the whole of the land-shells are peculiar. This seems to indicate that the

means of transmission were formerly greater than they are now, and that in

the case of land-shells none have been introduced for so long a period that

all have become modified into distinct forms, or have been preserved on the

island while they have become extinct on the continent. For a detailed

examination of the causes which have led to the modification of the humming

birds of Juan Fernandez see the chapter on Humming Birds in the author's

_Natural Selection and Tropical Nature_, p. 324; while a general account of

the fauna of the island is given in his _Geographical Distribution of

Animals_, Vol. II. p. 49.

[116] No additions appear to have been made to this flora down to 1885,

when Mr. Hemsley published his _Report on the Present State of our

Knowledge of Insular Floras_.

[117] _Journal of the Linnean Society_, Vol. XIII., "Botany," p. 556.

[118] _Geographical Distribution of Animals_, Vol. II. p. 81.

[119] _St. Helena: a Physical, Historical, and Topographical Description of

the Island, &c._ By John Charles Melliss, F.G.S., &c. London: 1875.

[120] Mr. Marsh in his interesting work entitled _The Earth as Modified by

Human Action_ (p. 51), thus remarks on the effect of browsing quadrupeds in

destroying and checking woody vegetation.--"I am convinced that forests

would soon cover many parts of the Arabian and African deserts if man and

domestic animals, especially the goat and the camel, were banished from

them. The hard palate and tongue, and strong teeth and jaws of this latter

quadruped enable him to break off and masticate tough and thorny branches

as large as the finger. He is particularly fond of the smaller twigs,

leaves, and seed-pods of the _Sont_ and other acacias, which, like the

American robinia, thrive well on dry and sandy soils, and he spares no tree

the branches of which are within his reach, except, if I remember right,

the tamarisk that produces manna. Young trees sprout plentifully around the

springs and along the winter water-courses of the desert, and these are

just the halting stations of the caravans and their routes of travel. In

the shade of these trees annual grasses and perennial shrubs shoot up, but

are mown down by the hungry cattle of the Bedouin as fast as they grow. A

few years of undisturbed vegetation would suffice to cover such points with

groves, and these would gradually extend themselves over soils where now

scarcely any green thing but the bitter colocynth and the poisonous

foxglove is ever seen."

[121] _Coleoptera Sanctae Helenae_, 1877; _Testacea Atlantica_, 1878.

[122] On Petermann's map of Africa, in _Stieler's Hand-Atlas_ (1879), the

Island of Ascension is shown as seated on a much larger and shallower

submarine bank than St. Helena. The 1,000 fathom line round Ascension

encloses an oval space 170 miles long by 70 wide, and even the 300 fathom

line, one over 60 miles long; and it is therefore probable that a much

larger island once occupied this site. Now Ascension is nearly equidistant

between St. Helena and Liberia, and such an island might have served as an

intermediate station through which many of the immigrants to St. Helena

passed. As the distances are hardly greater than in the case of the Azores,

this removes whatever difficulty may have been felt of the possibility of

_any_ organisms reaching so remote an island. The present island of

Ascension is probably only the summit of a huge volcanic mass, and any

remnant of the original fauna and flora it might have preserved may have

been destroyed by great volcanic eruptions. Mr. Darwin collected some

masses of tufa which were found to be mainly organic, containing, besides

remains of fresh-water infusoria, the siliceous tissue of plants! In the

light of the great extent of the submarine bank on which the island stands,

Mr. Darwin's remark, that--"we may feel sure, that at some former epoch,

the climate and productions of Ascension were very different from what they

are now,"--has received a striking confirmation. (See _Naturalist's Voyage

Round the World_, p. 495.)

[123] "Notes on the Classification, History, and Geographical Distribution

of Compositae."--_Journal of the Linnean Society_, Vol. XIII. p. 563

(1873).

[124] The Melhaniae comprise the two finest timber trees of St. Helena, now

almost extinct, the redwood and native ebony.

[125] _Journal of the Linnean Society_, 1873, p. 496. "On Diversity of

Evolution under one set of External Conditions." _Proceedings of the

Zoological Society of London_, 1873, p. 80. "On the Classification of the

Achitinellidae."

[126] "Memoirs on the Coleoptera of the Hawaiian Islands." By the Rev. T.

Blackburn, B.A., and Dr. D. Sharp. _Scientific Transactions of the Royal

Dublin Society._ Vol. III. Series II. 1885.

[127] See Hildebrand's _Flora of the Hawaiian Islands_, Introduction, p.

xiv.

[128] _Flora of the Hawaiian Islands_, by W. Hildebrand, M.D., annotated

and published after the author's death by W. F. Hildebrand, 1888.

[129] These are obtained from Hildebrand's _Flora_ supplemented by Mr.

Bentham's paper in the _Journal of the Linnean Society_.

[130] Among the curious features of the Hawaiian flora is the extraordinary

development of what are usually herbaceous plants into shrubs or trees.

Three species of Viola are shrubs from three to five feet high. A shrubby

Silene is nearly as tall; and an allied endemic genus, Schiedea, has

numerous shrubby species. _Geranium arboreum_ is sometimes twelve feet

high. The endemic Compositae are mostly shrubs, while several are trees

reaching twenty or thirty feet in height. The numerous Lobeliaceae, all

endemic, are mostly shrubs or trees, often resembling palms or yuccas in

habit, and sometimes twenty-five or thirty feet high. The only native genus

of Primulaceae--Lysimachia--consists mainly of shrubs; and even a plantain

has a woody stem sometimes six feet high.

[131] _Geological Magazine_, 1870, p. 155.

[132] _Transactions of the Edinburgh Geological Society_, Vol. I. p. 330.

[133] _Quarterly Journal of Geological Society_, 1850, p. 96.

[134] _British Association Report_, Dundee, 1867, p. 431.

[135] The list of names was furnished to me by Dr. Guenther, and I have

added the localities from the papers containing the original descriptions,

and from Dr. Haughton's _British Freshwater Fishes_.

[136] See "The Virginia Colony of Helix nemoralis," T. D. A. Cockerell, in

_The Nautilus_, Vol. III. No. 7, p. 73.

[137] I am indebted to Mr. Mitten for this curious fact.

[138] The following remarks by Dr. Richard Spruce, who has made a special

study of mosses and especially of hepaticae, are of interest. "From what

precedes, I conclude that no existing agency is capable of transporting the

germs of our hepatics of tropical type from the torrid zone to Britain, and

I venture to suppose that their existence at Killarney dates from the

remote period when the vegetation of the whole northern hemisphere partook

of a tropical character. If I am challenged to account for their survival

through the last glacial period, I reply that, granting even the existence

of a universal ice-cap down to the latitude of 40deg in America and 50deg

in Europe, it is not to be assumed that the whole extent, even of land, was

_perennially_ entombed 'in thrilling regions of thick-ribbed ice.' Towards

the southern margin of the ice the climate was probably very similar to

that of Greenland and the northern part of Norway at the present day. The

summer sun would have great power, and on the borders of sheltered fjords

the frozen snow would disappear completely, if only for a very short

period, and I ask only for a month or two, not doubting the capacity of our

hepatics to survive in a dormant state under the snow for at least ten

months in the year. I have gathered mosses in the Pyrenees where the snow

had barely left them on August 2nd; by September 25th they were re-covered

with snow, and would not be again uncovered till the following year. The

mosses of Killarney might even enjoy a longer summer than this; for the

gulf-stream laves both sides of the south-western angle of Ireland, and its

tepid waters would exert great melting power on the ice-bound coast,

preventing at the same time any formation of ice in the sea itself." This

passage is the conclusion of a very interesting discussion on the

distribution of hepaticae in a paper on "A New Hepatic from Killarney," in

the _Journal of Botany_, vol. 25, (Feb. 1887), pp. 33-82, in which many

curious facts are given as to the habits and distribution of these curious

and beautiful little plants.

[139] While these pages are passing through the press I am informed by my

friend Mr. W. H. Beeby that in the Shetland Isles, where he has been

collecting for five summers, he has found several plants new to the British

flora, and a few altogether undescribed. Among these latter is a very

distinct species of Hieracium (_H. Zetlandicum_), which is quite unknown in

Scandinavia, and is almost certainly peculiar to the British Islands. Here

we have another proof that entirely new species are still to be discovered

in the remoter portions of our country.

[140] In the first edition of this work the numbers were 400 and 340,

showing the great increase of our knowledge during the last ten years,

chiefly owing to the researches of Mr. A. H. Everett in Sarawak and Mr.

John Whitehead in North Borneo and the great mountain Kini Balu.

[141] These are Allocotops, Chlorocharis, Androphilus, and Ptilopyga, among

the Timeliidae; Tricophoropsis and Oreoctistes among the Brachypodidae;

Chlamydochoera among the Campophagidae.

[142] In a letter from Darwin he says:--"Hooker writes to me, 'Miguel has

been telling me that the flora of Sumatra and Borneo are identical, and

that of Java quite different.'"

[143] "On the Geology of Sumatra," by M. R. D. M. Verbeck. _Geological

Magazine_, 1877.

[144] _Pitta megarhynchus_ (Banca) allied to _P. brachyurus_ (Borneo,

Sumatra, Malacca); and _Pitta bangkanus_ (Banca) allied to _P. sordidus_

(Borneo and Sumatra).

[145] The following list of the mammalia of the Philippines and the Sulu

Islands has been kindly furnished me by Mr. Everett.

QUADRUMANA.

1. Macacus cynomolgus.

2. Tarsius spectrum.

CARNIVORA.

3. Viverra tangalunga.

4. Paradoxurus philippinensis. Also in Palawan.

5. Felis bengalensis. In Negros Island.

UNGULATA.

6. Bubalus mindorensis. Peculiar species.

7. Cervus philippinus. Peculiar species.

8. " alfredi. Peculiar species.

9. " nigricans. Peculiar species.

10. " pseudaxis. Sulu only. Probably introduced.

11. Sus marchesi. Peculiar species.

RODENTIA.

12. Sciurus philippinensis. Peculiar species.

13. Sciurus cagos. Peculiar species.

14. " concinnus. Peculiar. Mindanao and Basilan.

15. Phlaeomys cummingi. Peculiar genus.

16. Mus ephippium.

17. " everetti. Peculiar species.

INSECTIVORA.

18. Crocidura luzoniensis. Peculiar species.

19. Crocidura edwardsiana. Peculiar species.

20. Dendrogale sp.

21. Galeopithecus philippinensis. Peculiar species.

CHIROPTERA.

22. Pteropus leucopterus.

23. " edulis.

24. " hypomelanus.

25. " jubatus.

26. Xantharpyia amplexicaule.

27. Cynopterus marginatus.

28. " jagorii. Peculiar species.

29. Carponycteris australis.

30. Rhinolophus luctus.

31. " philippinensis. Peculiar species.

32. Rhinolophus rufus. Peculiar species.

33. Hipposideros diadema.

34. " pygmaeus. Peculiar species.

35. Hipposideros larvatus.

36. " obscurus. Peculiar species.

37. Hipposideros coronatus. Peculiar species.

38. Hipposideros bicolor.

39. Megaderma spasma.

40. Vesperugo pachypus.

41. " tenuis.

42. Vesperugo abramus.

43. Nycticejus kuhlii.

44. Vespertilio macrotarsus. Peculiar species.

45. Vespertilio capaccinii.

46. Harpiocephalus cyclotis.

47. Kerivoula hardwickii.

48. Kerivoula pellucida. Peculiar species.

49. " jagorii. Peculiar species.

50. Miniopterus schreibersii.

51. " tristis. Peculiar species.

52. Emballonura monticola.

53. Taphyzous melanopogon.

54. Nyctinomus plicatus.

[146] Extracted from Messrs. Blakiston and Pryer's _Catalogue of Birds of

Japan_ (_Ibis_, 1878, p. 209), with Mr. Seebohm's additions and corrections

in his _Birds of the Japanese Empire_ 1890. Accidental stragglers are not

reckoned as British birds.

[147] Mr. Swinhoe died in October, 1877, at the early age of forty-two. His

writings on natural history are chiefly scattered through the volumes of

the _Proceedings of the Zoological Society_ and _The Ibis_; the whole being

summarised in his _Catalogue of the Mammals of South China and Formosa_

(_P. Z. S._, 1870, p. 615), and his _Catalogue of the Birds of China and

its Islands_ (_P. Z. S._, 1871, p. 337).

[148] Captain Blakiston has shown that the northern island--Yezo--is much

more temperate and less peculiar in its zoology than the central and

southern islands. This is no doubt dependent chiefly on the considerable

change of climate that occurs on passing the Tsu-garu strait.

[149] See Dr. J. E. Gray's "Revision of the Viverridae," in _Proc. Zool.

Soc._ 1864, p. 507.

[150] Some of the Bats of Madagascar and East Africa are said to have their

nearest allies in Australia. (See Dobson in _Nature_, Vol. XXX. p. 575.)

[151] This view was, I believe, first advanced by Professor Huxley in his

"Anniversary Address to the Geological Society," in 1870. He says:--"In

fact the Miocene mammalian fauna of Europe and the Himalayan regions

contain, associated together, the types which are at present separately

located in the South African and Indian provinces of Arctogaea. Now there

is every reason to believe, on other grounds, that both Hindostan south of

the Ganges, and Africa south of the Sahara, were separated by a wide sea

from Europe and North Asia during the Middle and Upper Eocene epochs. Hence

it becomes highly probable that the well-known similarities, and no less

remarkable differences, between the present faunae of India and South

Africa have arisen in some such fashion as the following: Some time during

the Miocene epoch, the bottom of the nummulitic sea was upheaved and

converted into dry land in the direction of a line extending from Abyssinia

to the mouth of the Ganges. By this means the Dekkan on the one hand and

South Africa on the other, became connected with the Miocene dry land and

with one another. The Miocene mammals spread gradually over this

intermediate dry land; and if the condition of its eastern and western ends

offered as wide contrasts as the valleys of the Ganges and Arabia do now,

many forms which made their way into Africa must have been different from

those which reached the Dekkan, while others might pass into both these

sub-provinces."

This question is fully discussed in my _Geographical Distribution of

Animals_ (Vol. I., p. 285), where I expressed views somewhat different from

those of Professor Huxley, and made some slight errors which are corrected

in the present work. As I did not then refer to Professor Huxley's prior

statement of the theory of Miocene immigration into Africa (which I had

read but the reference to which I could not recall) I am happy to give his

views here.

[152] The total number of Madagascar birds is 238, of which 129 are

absolutely peculiar to the island, as are thirty-five of the genera. All

the peculiar birds but two are land birds. These are the numbers given in

M. Grandidier's great work on Madagascar.

[153] _The Ibis_, 1877, p. 334.

[154] In a paper read before the Geological Society in 1874, Mr. H. F.

Blanford, from the similarity of the fossil plants and reptiles, supposed

that India and South Africa had been connected by a continent, "and

remained so connected with some short intervals from the Permian up to the

end of the Miocene period," and Mr. Woodward expressed his satisfaction

with "this further evidence derived from the fossil flora of the Mesozoic

series of India in corroboration of the former existence of an old

submerged continent--Lemuria."

Those who have read the preceding chapters of the present work will not

need to have pointed out to them how utterly inconclusive is the

fragmentary evidence derived from such remote periods (even if there were

no evidence on the other side) as indicating geographical changes. The

notion that a similarity in the productions of widely separated continents

at any past epoch is only to be explained by the existence of a _direct_

land-connection, is entirely opposed to all that we know of the wide and

varying distribution of _all_ types at different periods, as well as to the

great powers of dispersal over moderate widths of ocean possessed by all

animals except mammalia. It is no less opposed to what is now known of the

general permanency of the great continental and oceanic areas; while in

this particular case it is totally inconsistent (as has been shown above)

with the actual facts of the distribution of animals.

[155] _Geographical Distribution of Animals_, Vol. I., pp. 272-292.

[156] The term "Mascarene" is used here in an extended sense, to include

all the islands near Madagascar which resemble it in their animal and

vegetable productions.

[157] For the birds of the Comoro Islands see _Proc. Zool. Soc._, 1877, p.

295, and 1879, p. 673.

[158] The following is a list of these peculiar birds. (See the _Ibis_, for

1867, p. 359; and 1879, p. 97.)

PASSERES.

_Ellisia seychelensis._

_Copsychus seychellarum._

_Hypsipetes crassirostris._

_Tchitrea corvina._

_Nectarinia dussumieri._

_Zosterops modesta._

" _semiflava._

_Foudia seychellarum._

PSITTACI.

_Coracopsis barklyi._

_Palaeornis wardi._

COLUMBAE.

_Alectoraenas pulcherrimus._

_Turtur rostratus._

ACCIPITRES.

_Tinnunculus gracilis._

[159] Specimens are recorded from West Africa in the _Proceedings of the

Academy of Natural Science_, Philadelphia, 1857, p. 72, while specimens in

the Paris Museum were brought by D'Orbigny from S. America. Dr. Wright's

specimens from the Seychelles have, as he informs me, been determined to be

the same species by Dr. Peters of Berlin.

[160] "Additional Notes on the Land-shells of the Seychelles Islands." By

Geoffrey Nevill, C.M.Z.S. _Proc. Zool. Soc._ 1869, p. 61.

[161] In Maillard's _Notes sur l'Isle de Reunion_, a considerable number of

mammalia are given as "wild," such as _Lemur mongoz_ and _Centetes

setosus_, both Madagascar species, with such undoubtedly introduced animals

as a wild cat, a hare, and several rats and mice. He also gives two species

of frogs, seven lizards, and two snakes. The latter are both Indian species

and certainly imported, as are most probably the frogs. Legouat, who

resided some years in the island nearly two centuries ago, and who was a

closer observer of nature, mentions numerous birds, large bats,

land-tortoises, and lizards, but no other reptiles or venomous animals

except scorpions. We may be pretty sure, therefore, that the land-mammalia,

snakes, and frogs, now found wild, have all been introduced. Of lizards, on

the other hand, there are several species, some peculiar to the island,

others common to Africa and the other Mascarene Islands. The following list

by Prof. Dumeril is given in Maillard's work:--

_Platydactylus cepedianus._

" _ocellatus._

_Hemidactylus peronii._

" _mutilatus._

_Hemidactylus frenatus._

_Gongylus bojerii._

_Ablepharus peronii._

Four species of chameleon are now recorded from Bourbon and one from

Mauritius (J. Reay Greene, M.D., in _Pop. Science Rev._ April, 1880), but

as they are not mentioned by the old writers, it is pretty certain that

these creatures are recent introductions, and this is the more probable as

they are favourite domestic pets.

Darwin informed me that in a work entitled _Voyage a l'Isle de France, par

un Officier du Roi_, published in 1770, it is stated that a fresh-water

fish had been introduced from Batavia and had multiplied. The writer also

says (p. 170): "_On a essaye, mais sans succces, d'y transporter des

grenouilles qui mangent les oeufs que les moustigues deposent sur les eaux

stagnantes._" It thus appears that there were then no frogs on the island.

[162] That the dodo is really an abortion from a more perfect type, and not

a direct development from some lower form of wingless bird, is shown by its

possessing a keeled sternum, though the keel is exceedingly reduced, being

only three-quarters of an inch deep in a length of seven inches. The most

terrestrial pigeon--the Didunculus of the Samoan Islands, has a far deeper

and better developed keel, showing that in the case of the dodo the

degradation has been extreme. We have also analogous examples in other

extinct birds of the same group of islands, such as the flightless

Rails--Aphanapteryx of Mauritius and Erythromachus of Rodriguez, as well as

the large parrot--Lophopsittacus of Mauritius, and the Night Heron,

_Nycticorax megacephala_ of Rodriguez, the last two birds probably having

been able to fly a little. The commencement of the same process is to be

seen in the peculiar dove of the Seychelles, _Turtur rostratus_, which, as

Mr. Edward Newton has shown, has much shorter wings than its close ally,

_T. picturatus_, of Madagascar. For a full and interesting account of these

and other recently extinct birds see Professor Newton's article on "Fossil

Birds" in the _Encyclopaedia Britannica_, ninth edition, vol. iii., p. 732;

and that on "The Extinct Birds of Rodriguez," by Dr. A. Guenther and Mr. E.

Newton, in the Royal Society's volume on the Transit of Venus Expedition.

[163] See _Ibis_, 1877, p. 334.

[164] A common Indian and Malayan toad (_Bufo melanostictus_) has been

introduced into Mauritius and also some European toads, as I am informed by

Dr. Guenther.

[165] This brief account of the Madagascar flora has been taken from a very

interesting paper by the Rev. Richard Baron, F.L.S., F.G.S., in the

_Journal of the Linnean Society_, Vol. XXV., p. 246; where much information

is given on the distribution of the flora within the island.

[166] It may be interesting to botanists and to students of geographical

distribution to give here an enumeration of the endemic genera of the

_Flora of the Mauritius and the Seychelles_, as they are nowhere separately

tabulated in that work.

Aphloia (Bixaceae) 1 sp., a shrub, Maur., Rod., Sey., also

Madagascar.

Medusagyne (Ternstroemiaceae) 1 sp., a shrub, Seychelles.

Astiria (Sterculiaceae) 1 sp., a shrub, Mauritius.

Quivisia (Meliaceae) 3 sp., shrubs, Mauritius (2 sp.),

Rodriguez (1 sp.), also Bourbon.

Cossignya (Sapindaceae) 1 sp., a shrub, Mauritius, also Bourbon.

Hornea ,, 1 sp., a shrub, Mauritius.

Stadtmannia ,, 1 sp., a shrub, Mauritius.

Doratoxylon ,, 1 sp., a shrub, Mauritius and Bourbon.

Gagnebina (Leguminosae) 1 sp., a shrub, Mauritius, also

Madagascar.

Roussea (Saxifragaceae) 1 sp., a climbing shrub, Mauritius and

Bourbon.

Tetrataxis (Lythraceae) 1 sp., a shrub, Mauritius.

Psiloxylon ,, 1 sp., a shrub, Mauritius and Bourbon.

Mathurina (Turneraceae) 1 sp., a shrub, Rodriguez.

Foetidia (Myrtaceae) 1 sp., a tree, Mauritius.

Danais (Rubiaceae) 4 sp., climbing shrubs, Maur. (1 sp.),

Rodr. (1 sp.), also Bourbon and

Madagascar.

Fernelia (Rubiaceae) 1 sp., a shrub, Mauritius and Rodriguez.

Pyrostria ,, 6 sp., shrubs, Mauritius (3 sp.), also

Bourbon and Madagascar.

Scyphochlamys (Rubiaceae) 1 sp., a shrub, Rodriguez.

Myonima ,, 3 sp., shrubs, Mauritius, also Bourbon.

Cylindrocline (Compositae) 1 sp., a shrub, Mauritius.

Monarrhenus ,, 2 sp., shrubs, Mauritius, also Bourbon

and Madagascar.

Faujasia (Compositae) 3 sp., shrubs, Mauritius, also Bourbon

and Madagascar.

Heterochaenia (Campanulaceae) 1 sp., a shrub, Mauritius, also Bourbon.

Tanulepis (Asclepiadaceae) 1 sp., a climber, Rodriguez.

Decanema ,, 1 sp., a climber, Mauritius, also

Madagascar.

Nicodemia (Loganiaceae) 2 sp., shrubs, Mauritius (1 sp.), also

Comoro Islands and Madagascar.

Bryodes (Scrophulariaceae) 1 sp., herb, Mauritius.

Radamaea ,, 2 sp., herb, Seychelles (1 sp.), and

Madagascar.

Colea (Bignoniaceae) 10 sp., Mauritius (1 sp.), Seychelles (1

sp.), also Bourbon and Madagascar.

(Shrubs, trees, or climbers.)

Obetia (Urticaceae) 2 sp., shrubs, Mauritius, Seychelles,

and Madagascar.

Bosquiea (Moreae) 3 sp., trees, Seychelles (1 sp.), also

Madagascar.

Monimia (Monimiaceae) 3 sp., trees, Mauritius (2 sp.), also

Bourbon.

Cynorchis (Orchideae) 3 sp., herb, ter., Mauritius.

Amphorchis ,, 1 sp., herb, ter., Mauritius, also

Bourbon.

Arnottia ,, 2 sp., herb, ter., Mauritius, also

Bourbon.

Aplostellis ,, 1 sp., herb, ter., Mauritius.

Cryptopus ,, 1 sp., herb, Epiphyte, Mauritius, also

Bourbon and Madagascar.

Lomatophyllum (Liliaceae) 3 sp., shrubs (succulent), Mauritius,

also Bourbon.

Lodoicea (Palmae) 1 sp., tree, Seychelles.

Latania ,, 3 sp., trees, Mauritius (2 sp.),

Rodriguez, also Bourbon.

Hyophorbe ,, 3 sp., trees, Mauritius (2 sp.),

Rodriguez, also Bourbon.

Dictyosperma ,, 1 sp., tree, Mauritius, Rodriguez,

also Bourbon.

Acanthophaenix ,, 2 sp., trees, Mauritius, also Bourbon.

Deckenia ,, 1 sp., tree, Seychelles.

Nephrosperma ,, 1 sp., tree, Seychelles.

Roscheria ,, 1 sp., tree, Seychelles.

Verschaffeltia ,, 1 sp., tree, Seychelles.

Stevensonia ,, 1 sp., tree, Seychelles.

Ochropteris (Filices) 1 sp., herb, Mauritius, also Bourbon and

Madagascar.

Among the curious features in this list are the great number of endemic

shrubs in Mauritius, and the remarkable assemblage of five endemic genera

of palms in the Seychelles Islands. We may also notice that one palm

(_Latania loddigesii_) is confined to Round Island and two other adjacent

islets offering a singular analogy to the peculiar snake also found there.

[167]

_Families of Malayan Birds not found in islands East of Celebes._

Troglodytidae.

Sittidae.

Paridae.

Liotrichidae.

Phyllornithidae.

Eurylaemidae.

Picidae.

Indicatoridae.

Megalaenidae.

Trogonidae.

Phasianidae.

_Families of Moluccan Birds not found in islands West of Celebes._

Paradiseidae.

Meliphagidae.

Cacatuidae.

Platycercidae.

Trichoglossidae.

Nestoridae.

[168] For outline figures of the chief types of these butterflies, see my

_Malay Archipelago_, Vol. I. p. 441, or p. 216 of the tenth edition.

[169] Dobson on the Classification of Chiroptera (_Ann. and Mag. of Nat.

Hist._ Nov. 1875).

[170] See Buller, "On the New Zealand Rat," _Trans. of the N. Z. Institute_

(1870), Vol. III. p. 1, and Vol. IX. p. 348; and Hutton, "On the

Geographical Relations of the New Zealand Fauna," _Trans. N. Z. Instit._

1872, p. 229.

[171] Hochstetter's _New Zealand_, p. 161, note.

[172] The animal described by Captain Cook as having been seen at

Pickersgill Harbour in Dusky Bay (Cook's 2nd Voyage, Vol. I. p. 98) may

have been the same creature. He says, "A four-footed animal was seen by

three or four of our people, but as no two gave the same description of it,

I cannot say what kind it is. All, however, agreed that it was about the

size of a cat, with short legs, and of a mouse colour. One of the seamen,

and he who had the best view of it, said it had a bushy tail, and was the

most like a jackal of any animal he knew." It is suggestive that, so far as

the points on which "all agreed"--the size and the dark colour--this

description would answer well to the animal so recently seen, while the

"short legs" correspond to the otter-like tracks, and the thick tail of an

otter-like animal may well have appeared "bushy" when the fur was dry. It

has been suggested that it was only one of the native dogs; but as none of

those who saw it took it for a dog, and the points on which they all agreed

are not dog-like, we can hardly accept this explanation; while the actual

existence of an unknown animal in New Zealand of corresponding size and

colour is confirmed by this account of a similar animal having been seen

about a century ago.

[173] Owen, "On the Genus Dinornis," _Trans. Zool. Soc._ Vol. X. p. 184.

Mivart, "On the Axial Skeleton of the Struthionidae," _Trans. Zool. Soc._

Vol. X. p. 51.

[174] The recent existence of the Moa and its having been exterminated by

the Maoris appears to be at length set at rest by the statement of Mr. John

White, a gentleman who has been collecting materials for a history of the

natives for thirty-five years, who has been initiated by their priests into

all their mysteries, and is said to "know more about the history, habits,

and customs of the Maoris than they do themselves." His information on this

subject was obtained from old natives long before the controversy on the

subject arose. He says that the histories and songs of the Maoris abound in

allusions to the Moa, and that they were able to give full accounts of "its

habits, food, the season of the year it was killed, its appearance,

strength, and all the numerous ceremonies which were enacted by the natives

before they began the hunt, the mode of hunting, how cut up, how cooked,

and what wood was used in the cooking, with an account of its nest, and how

the nest was made, where it usually lived, &c." Two pages are occupied by

these details, but they are only given from memory, and Mr. White promises

a full account from his MSS. Many of the details given correspond with

facts ascertained from the discovery of native cooking places with Moas'

bones; and it seems quite incredible that such an elaborate and detailed

account should be all invention. (See _Transactions of the New Zealand

Institute_, Vol. VIII. p. 79.)

[175] See fig. in _Trans. of N. Z. Institute_, Vol. III., plate 12_b._ fig.

2.

[176] _Geographical Distribution of Animals_, Vol. I., p. 450.

[177] In my _Geographical Distribution of Animals_ (I. p. 541) I have given

two peculiar Australian genera (_Orthonyx_ and _Tribonyx_) as occurring in

New Zealand. But the former has been found in New Guinea, while the New

Zealand bird is considered to form a distinct genus, _Clitonyx_; and the

latter inhabits Tasmania, and was recorded from New Zealand through an

error. (See _Ibis_, 1873, p. 427.)

[178] The peculiar genera of Australian lizards according to Boulenger's

British Museum Catalogue, are as follows:--Family GECKONIDAE: Nephrurus,

Rhynchoedura, Heteronota, Diplodactylus, Oedura. Family PYGOPODIDAE

(peculiar): Pygopus, Cryptodelma, Delma, Pletholax, Aprasia. Family

AGAMIDAE: Chelosania, Amphibolurus, Tympanocryptis, Diporophora,

Chlamydosaurus, Moloch, Oreodeira. Family SCINCIDAE: Egerina, Trachysaurus,

Hemisphaenodon. Family doubtful: Ophiopsiseps.

[179] These figures are taken from Mr. G. M. Thomson's address "On the

Origin of the New Zealand Flora," _Trans. N. Z. Institute_, XIV. (1881),

being the latest that I can obtain. They differ somewhat from those given

in the first edition, but not so as to affect the conclusions drawn from

them.

[180] This accords with the general scarcity of Leguminosae in Oceanic

Islands, due probably to their usually dry and heavy seeds, not adapted to

any of the forms of aerial transmission; and it would indicate either that

New Zealand was never absolutely united with Australia, or that the union

was at a very remote period when Leguminosae were either not differentiated

or comparatively rare.

[181] Sir Joseph Hooker informs me that the number of tropical Australian

plants discovered within the last twenty years is very great, and that the

statement as above made may have to be modified. Looking, however, at the

enormous disproportion of the figures given in the "Introductory Essay" in

1859 (2,200 tropical to 5,800 temperate species) it seems hardly possible

that a great difference should not still exist, at all events as regards

species. In Baron von Mueeller's latest summary of the Australian Flora

(_Second Systematic Census of Australian Plants_, 1889), he gives the total

species at 8,839, of which 3,560 occur in West Australia, and 3,251 in New

South Wales. On counting the species common to these two colonies in fifty

pages of the _Census_ taken at random, I find them to be about one-tenth of

the total species in both. This would give the number of distinct species

in these areas as about 6,130. Adding to these the species peculiar to

Victoria and South Australia, we shall have a flora of near 6,500 in the

temperate parts of Australia. It is true that West Australia extends far

into the tropics, but an overwhelming majority of the species have been

discovered in the south-western portion of the colony, while the species

that may be exclusively tropical will be more than balanced by those of

temperate Queensland, which have not been taken account of, as that colony

is half temperate and half tropical. It thus appears probable that full

three fourths of the species of Australian plants occur in the temperate

regions, and are mainly characteristic of it. Sir Joseph Hooker also doubts

the generally greater richness of tropical over temperate floras which I

have taken as almost an axiom. He says: "Taking similar areas to Australia

in the Western World, _e.g._, tropical Africa north of 20deg S. Lat. as

against temperate Africa and Europe up to 47deg--I suspect that the latter

would present more genera and species than the former." This, however,

appears to me to be hardly a case in point, because Europe is a distinct

continent from Africa and has had a very different past history, and it is

not a fair comparison to take the tropical area in one continent while the

temperate is made up of widely separated areas in two continents. A closer

parallel may perhaps be found in equal areas of Brazil and south temperate

America, or of Mexico and the Southern United States, in both of which

cases I suppose there can be little doubt that the tropical areas are far

the richest. Temperate South Africa is, no doubt, always quoted as richer

than an equal area of tropical Africa or perhaps than any part of the world

of equal extent, but this is admitted to be an exceptional case.

[182] Sir Joseph Hooker thinks that later discoveries in the Australian

Alps and other parts of East and South Australia may have greatly modified

or perhaps reversed the above estimate, and the figures given in the

preceding note indicate that this is so. But still, the small area of

South-west Australia will be, proportionally, far the richer of the two. It

is much to be desired that the enormous mass of facts contained in Mr.

Bentham's _Flora Australiensis_ and Baron von Mueeller's _Census_ should be

tabulated and compared by some competent botanist, so as to exhibit the

various relations of its wonderful vegetation in the same manner as was

done by Sir Joseph Hooker with the materials available twenty-one years

ago.

[183] From an examination of the fossil corals of the South-west of

Victoria, Professor P. M. Duncan concludes--"that, at the time of the

formation of these deposits the central area of Australia was occupied by

sea, having open water to the north, with reefs in the neighbourhood of

Java." The age of these fossils is not known, but as almost all are extinct

species, and some are almost identical with European Pliocene and Miocene

species, they are supposed to belong to a corresponding period. (_Journal

of Geol. Soc._, 1870.)

[184] "On the Origin of the Fauna and Flora of New Zealand," by Captain

F. W. Hutton, in _Annals and Mag. of Nat. Hist._ Fifth series, p. 427

(June, 1884).

[185] To these must now be added the genera Sequoia, Myrica, Aralia, and

Acer, described by Baron von Ettingshausen. (_Trans. N.Z. Institute_, xix.,

p. 449.)

[186] The large collection of fossil plants from the Tertiary beds of New

Zealand which have been recently described by Baron von Ettingshausen

(_Trans. N. Z. Inst._, vol. xxiii., pp. 237-310), prove that a change in

the vegetation has occurred similar to that which has taken place in

Eastern Australia, and that the plants of the two countries once resembled

each other more than they do now. We have, first, a series of groups now

living in Australia, but which have become extinct in New Zealand, as

Cassia, Dalbergia, Eucalyptus, Diospyros, Dryandra, Casuarina, and Ficus;

and also such northern genera as Acer, Planera, Ulmus, Quercus, Alnus,

Myrica, and Sequoia. All these latter, except Ulmus and Planera, have been

found also in the Eastern-Australian Tertiaries, and we may therefore

consider that at this period the northern temperate element in both floras

was identical. If this flora entered both countries from the south, and was

really Antarctic, its extinction in New Zealand may have been due to the

submergence of the country to the south, and its elevation and extension

towards the tropics, admitting of the incursion of the large number of

Polynesian and tropical Australian types now found there; while the

Australian portion of the same flora may have succumbed at a somewhat later

period, when the elevation of the Cretaceous and Tertiary sea united it

with Western Australia, and allowed the rich typical Australian flora to

overrun the country. Of course we are assuming that the identification of

these genera is for the most part correct, though almost entirely founded

on leaves only. Fuller knowledge, both of the extinct flora itself and of

the geological age of the several deposits, is requisite before any

trustworthy explanation of the phenomena can be arrived at.

[187] The following are the tropical genera common to New Zealand and

Australia:--

1. _Melicope._ Queensland, Pacific Islands.

2. _Eugenia._ Eastern and Tropical Australia, Asia, and America.

3. _Passiflora._ N.S.W. and Queensland, Tropics of Old World and America.

4. _Myrsine._ Tropical and Temperate Australia, Tropical and Sub-tropical

regions.

5. _Sapota._ Australia, Norfolk Islands, Tropics.

6. _Cyathodes._ Australia and Pacific Islands.

7. _Parsonsia._ Tropical Australia and Asia.

8. _Geniostoma._ Queensland, Polynesia, Asia.

9. _Mitrasacme._ Tropical and Temperate Australia, India.

10. _Ipomoea._ Tropical Australia, Tropics.

11. _Mazus._ Temperate Australia, India, China.

12. _Vitex._ Tropical Australia, Tropical and Sub-tropical.

13. _Pisonia._ Tropical Australia, Tropical and Sub-tropical.

14. _Alternanthera._ Tropical Australia, India, and S. America.

15. _Tetranthera._ Tropical Australia, Tropics.

16. _Santalum._ Tropical and Sub-tropical Australia, Pacific, Malay

Islands.

17. _Carumbium._ Tropical and Sub-tropical Australia, Pacific Islands.

18. _Elatostemma._ Sub-tropical Australia, Asia, Pacific Islands.

19. _Peperomia._ Tropical and Sub-tropical Australia, Tropics.

20. _Piper._ Tropical and Sub-tropical Australia, Tropics.

21. _Dacrydium._ Tasmania, Malay, and Pacific Islands.

22. _Dammara._ Tropical Australia, Malay, and Pacific Islands.

23. _Dendrobium._ Tropical Australia, Eastern Tropics.

24. _Bolbophyllum._ Tropical and Sub-tropical Australia, Tropics.

25. _Sarcochilus._ Tropical and Sub-tropical Australia, Fiji, and Malay

Islands.

26. _Freycinetia._ Tropical Australia, Tropical Asia.

27. _Cordyline._ Tropical Australia, Pacific Islands.

28. _Dianella._ Australia, India, Madagascar, Pacific Islands.

29. _Cyperus._ Australia, Tropical regions mainly.

30. _Fimbristylis._ Tropical Australia, Tropical regions.

31. _Paspalum._ Tropical and Sub-tropical grasses.

32. _Isachne._ Tropical and Sub-tropical grasses.

33. _Sporobolus._ Tropical and Sub-tropical grasses.

[188] Insects are tolerably abundant in the open mountain regions, but very

scarce in the forests. Mr. Meyrick says that these are "strangely deficient

in insects, the same species occurring throughout the islands;" and Mr.

Pascoe remarked that "the forests of New Zealand were the most barren

country, entomologically, he had ever visited." (_Proc. Ent. Soc._, 1883.

p. xxix.)

[189] Introductory Essay _On the Flora of Australia_, p. 130.

[190] Hooker, _On the Flora of Australia_, p. 95.--H. C. Watson, in

Godman's _Azores_, pp. 278-286.

[191] As this is a point of great interest in its bearing on the dispersal

of plants by means of mountain ranges, I have endeavoured to obtain a few

illustrative facts:--

1. Mr. William Mitten, of Hurstpierpoint, Sussex, informs me that when the

London and Brighton railway was in progress in his neighbourhood,

_Melilotus vulgaris_ made its appearance on the banks, remained for several

years, and then altogether disappeared. Another case is that of _Diplotaxis

muralis_, which formerly occurred only near the sea-coast of Sussex, and at

Lewes; but since the railway was made has spread along it, and still

maintains itself abundantly on the railway banks though rarely found

anywhere else.

2. A correspondent in Tasmania informs me that whenever the virgin forest

is cleared in that island there invariably comes up a thick crop of a plant

locally known as fire-weed--a species of Senecio, probably _S. Australis_.

It never grows except where the fire has gone over the ground, and is

unknown except in such places. My correspondent adds:--"This autumn I went

back about thirty-five miles through a dense forest, along a track marked

by some prospectors the year before, and in one spot where they had camped,

and the fire had burnt the fallen logs, &c., there was a fine crop of

'fire-weed.' All around for many miles was a forest of the largest trees

and dense scrub." Here we have a case in which burnt soil and ashes favour

the germination of a particular plant, whose seeds are easily carried by

the wind, and it is not difficult to see how this peculiarity might favour

the dispersal of the species for enormous distances, by enabling it

temporarily to grow and produce seeds on burnt spots.

3. In answer to an inquiry on this subject, Mr. H. C. Watson has been kind

enough to send me a detailed account of the progress of vegetation on the

railway banks and cuttings about Thames Ditton. This account is written

from memory, but as Mr. Watson states that he took a great interest in

watching the process year by year, there can be no reason to doubt the

accuracy of his memory. I give a few extracts which bear especially on the

subject we are discussing.

"One rather remarkable biennial plant appeared early (the second year, as I

recollect) and renewed itself either two or three years, namely, _Isatis

tinctoria_--a species usually supposed, to be one of our introduced, but

pretty well naturalised, plants. The nearest stations then or since known

to me for this _Isatis_ are on chalk about Guildford, twenty miles distant.

There were two or three plants of it at first, never more than half a

dozen. Once since I saw a plant of _Isatis_ on the railway bank near

Vauxhall.

"Close by Ditton Station three species appeared which may be called

interlopers. The biennial _Barbarea precox_, one of these, is the least

remarkable, because it might have come as seed in the earth from some

garden, or possibly in the Thames gravel (used as ballast). At first it

increased to several plants, then became less numerous, and will soon, in

all probability, become extinct, crowded out by other plants. The biennial

_Petroselinum segetum_ was at first one very luxuriant plant on the slope

of the embankment. It increased by seed into a dozen or a score, and is now

nearly if not quite extinct. The third species is _Linaria purpurea_, not

strictly a British plant, but one established in some places on old walls.

A single root of it appeared on the chalk facing of the embankment by

Ditton Station. It has remained there several years and grown into a

vigorous specimen. Two or three smaller examples are now seen by it,

doubtless sprung from some of the hundreds or thousands of seeds shed by

the original one plant. The species is not included in Salmon and Brewer's

_Flora of Surrey_.

"The main line of the railway has introduced into Ditton parish the

perennial _Arabis hirsuta_, likely to become a permanent inhabitant. The

species is found on the chalk and greensand miles away from Thames Ditton;

but neither in this parish nor in any adjacent parish, so far as known to

myself or to the authors of the flora of the county, does it occur. Some

years after the railway was made a single root of this _Arabis_ was

observed in the brickwork of an arch by which the railway is carried over a

public road. A year or two afterwards there were three or four plants. In

some later year I laid some of the ripened seed-pods between the bricks in

places where the mortar had partly crumbled out. Now there are several

scores of specimens in the brickwork of the arch. It is presumable that the

first seed may have been brought from Guildford. But how could it get on to

the perpendicular face of the brickwork?

"The Bee Orchis (_Ophrys apifera_), plentiful on some of the chalk lands in

Surrey, is not a species of Thames Ditton, or (as I presume) of any

adjacent parish. Thus, I was greatly surprised some years back to see about

a hundred examples of it in flower in one clayey field either on the

outskirts of Thames Ditton or just within the limits of the adjoining

parish of Cobham. I had crossed this same field in a former year without

observing the Ophrys there. And on finding it in the one field I closely

searched the surrounding fields and copses, without finding it anywhere

else. Gradually the plants became fewer and fewer in that one field, and

some six or eight years after its first discovery there the species had

quite disappeared again. I guessed it had been introduced with chalk, but

could obtain no evidence to show this."

4. Mr. A. Bennett, of Croydon, has kindly furnished me with some

information on the temporary vegetation of the banks and cuttings on the

railway from Yarmouth to Caistor in Norfolk, where it passes over extensive

sandy Denes with a sparse vegetation. The first year after the railway was

made the banks produced abundance of _Oenothera odorata_ and _Delphinium

Ajacis_ (the latter only known thirty miles off in cornfields in

Cambridgeshire), with _Atriplex patula_ and _A. deltoidea_. Gradually the

native sand plants--Carices, Grasses, _Galium verum_, &c., established

themselves, and year by year covered more ground till the new introductions

almost completely disappeared. The same phenomenon was observed in

Cambridgeshire between Chesterton and Newmarket, where, the soil being

different, _Stellaria media_ and other annuals appeared in large patches;

but these soon gave way to a permanent vegetation of grasses, composites,

&c., so that in the third year no _Stellaria_ was to be seen.

5. Mr. T. Kirk (writing in 1878) states that--"in Auckland, where a dense

sward of grass is soon formed, single specimens of the European milk

Thistle (_Carduus marianus_) have been known for the past fifteen years;

but although they seeded freely, the seeds had no opportunity of

germinating, so that the thistle did not spread. A remarkable exception to

this rule occurred during the formation of the Onehunga railway, where a

few seeds fell on disturbed soil, grew up and flowered. The railway works

being suspended, the plant increased rapidly, and spread wherever it could

find disturbed soil."

Again:--"The fiddle-dock (_Rumex pulcher_) occurs in great abundance on the

formation of new streets, &c., but soon becomes comparatively rare. It

seems probable that it was one of the earliest plants naturalised here, but

that it partially died out, its buried seeds retaining their vitality."

_Medicago sativa_ and _Apium graveolens_, are also noted as escapes from

cultivation which maintain themselves for a time but soon die out.

(_Transactions of the New Zealand Institute_, Vol. X. p. 367.)

The preceding examples of the _temporary_ establishment of plants on newly

exposed soil, often at considerable distances from the localities they

usually inhabit, might, no doubt, by further inquiry be greatly multiplied;

but, unfortunately, the phenomenon has received little attention, and is

not even referred to in the elaborate work of De Candolle (_Geographie

Botanique Raisonnee_) in which almost every other aspect of the dispersion

and distribution of plants is fully discussed. Enough has been advanced,

however, to show that it is of constant occurrence, and from the point of

view here advocated it becomes of great importance in explaining the almost

world-wide distribution of many common plants of the north temperate zone.

[192] Sir Joseph Hooker informs me that he considers these identifications

worthless, and Mr. Bentham has also written very strongly against the value

of similar identifications by Heer and Unger. Giving due weight to the

opinions of these eminent botanists we must admit that Australian genera

have not yet been _demonstrated_ to have existed in Europe during the

Tertiary period; but, on the other hand, the evidence that they did so

appears to have some weight, on account of the improbability that the

numerous resemblances to Australian plants which have been noticed by

different observers should _all_ be illusory; while the well established

fact of the former wide distribution of many tropical or now restricted

types of plants and animals, so frequently illustrated in the present

volume, removes the antecedent improbability which is supposed to attach to

such identifications. I am myself the more inclined to accept them,

because, according to the views here advocated, such migrations must have

taken place at remote as well as at recent epochs; and the preservation of

some of these types in Australia while they have become extinct in Europe,

is exactly paralleled by numerous facts in the distribution of animals

which have been already referred to in Chapter XIX., and elsewhere in this

volume, and also repeatedly in my larger work.

[193] Out of forty-two genera from the Eocene of Sheppey enumerated by Dr.

Ettingshausen in the _Geological Magazine_ for January 1880, only two or

three appear to be extinct, while there is a most extraordinary

intermixture of tropical and temperate forms--Musa, Nipa, and Victoria,

with Corylus, Prunus, Acer, &c. The rich Miocene flora of Switzerland,

described by Professor Heer, presents a still larger proportion of living

genera.

[194] The recent discovery by Lieutenant Jensen of a rich flora on rocky

peaks rising out of the continental ice of Greenland, as well as the

abundant vegetation of the highest northern latitudes, renders it possible

that even now the Antarctic continent may not be wholly destitute of

vegetation, although its climate and physical condition are far less

favourable than those of the Arctic lands. (See _Nature_, Vol. XXI. p.

345.)

[195] Dr. Hector notes the occurrence of the genus _Dammara_ in Triassic

deposits, while in the Jurassic period New Zealand possessed the genera

_Palaeozamia_, _Oleandrium_, _Alethopteris_, _Camptopteris_, _Cycadites_,

_Echinostrobus_, &c., all Indian forms of the same age. Neocomian beds

contain a true dicotyledonous leaf with _Dammara_ and _Araucaria_. The

Cretaceous deposits have produced a rich flora of dicotyledonous plants,

many of which are of the same genera as the existing flora; while the

Miocene and other Tertiary deposits produce plants almost identical with

those now inhabiting the country, together with many North Temperate genera

which have since become extinct. (See p. 499, footnote, and _Trans. New

Zealand Inst._, Vol. XI. 1879, p. 536.)

[196] The fact stated in the last edition of the _Origin of Species_ (p.

340) on the authority of Sir Joseph Hooker, that Australian plants are

rapidly sowing themselves and becoming naturalised on the Neilgherrie

mountains in the southern part of the Indian Peninsula, though an exception

to the rule of the inability of Australian plants to become naturalised in

the Northern Hemisphere, is yet quite in harmony with the hypothesis here

advocated. For not only is the climate of the Neilgherries more favourable

to Australian plants than any part of the North Temperate zone, but the

entire Indian Peninsula has existed for unknown ages as an _island_ and

thus possesses the "insular" characteristic of a comparatively poor and

less developed flora and fauna as compared with the truly "continental"

Malayan and Himalayan regions. Australian plants are thus enabled to

compete with those of the Indian Peninsula highlands with a fair chance of

success.

* * * * *

Corrections made to printed original.

Page 10. "the general stability of continents": 'sontinents' in original.

Pages 35, 250, 361, 363 "oenanthe" read for "aenanthe" throughout for

consistency

Page 50. "some others of the lower animals": 'animials' in original.

Page 82. "transmission along mountain chains": 'mountains chains' in

original.

Page 99. "our present land masses": 'massses' in original.

Page 149. "the whole earth should theoretically be": 'thoretically' in

original.

Page 200. "the flora and fauna, in the British area": 'Brittish' in

original.

Page 234. "the indications of an uninterrupted warm climate": 'indic-tions'

on line break in original.

Page 306. "artificially removed by man": 'artifically' in original.

Page 346. "Elachista rufocinerea, the larva of which ...": 'lava' in

original.

Page 456. "Cynopithecus nigrescens": 'Cynopitheus' in original.

Footnote 100. "S. B. J. Skertchley": 'S. B. K.' in original. I have left

the name as Skertchley as Wallace uses this spelling almost consistently,

although Skertchly (as on p. 118) appears to be correct.--Tr.

Footnote 105. "the transportation of the plants": 'transporation' in

original.

Footnote 110. "Agriolimax campestris": 'Agriolimaoe' (ligand oe) in

original.