In respect of their botanical relationsh_Journal of a tour in Marocco and the Great Atlas

Continents, Islands or Archipelagos may be roughly classed under

two divisions: namely, those which are situated within a moderate

distance of continents, and whose Floras are manifestly derived

from them or have had a common origin with theirs; and those which

are situated very far from any continents, and whose Floras differ

so much either from that of the neighbouring continent or from that

of those parts of the continent that are nearest to them, that their

origin is a matter of speculation. Of the first division, the British

Isles, and probably Vancouver’s Island, in North-West America,

are conspicuous instances, their Floras being almost identical with

those of the neighbouring continents. St. Helena, the Galapagos,

Mauritius, and the Sandwich Islands are instances of the opposite

extreme, for their Floras differ widely from those of any continents.

Between these extreme cases there are many intermediate ones; and

there are others of an exceptional character, as Iceland, which,

though far removed from any part of Europe, has but one flowering

plant not found on that continent (_Platanthera hyperborea_);

and Ceylon, which though it is almost united to the Peninsula of

Hindostan, yet in many respects differs greatly from that peninsula

in its Flora.

Amongst the exceptional cases to continental proximity being

accompanied by close botanical relationship is the Flora of the

Canarian Archipelago, which differs so greatly from that of the

northern part of its neighbouring continent, namely, from that

of Marocco,[1] that it demands notice in any work treating of the

vegetation of the latter country.

This diversity between the Maroccan and Canarian Floras has

been pointed out in Ball’s ‘Introductory Observations to the

Spicilegium Floræ Maroccanæ,’[2] where it appears that whilst

Marocco, out of 1,627 species of flowering plants, contains 165

endemic plants, it has only 15 which are confined to it and to the

Canaries, or to it and Madeira. And Ball goes on to remark (p. 301),

in respect of these few species common to both Floras: ‘I think

it is safe to say that the facts rather tend to show the accidental

diffusion of a few Macaronesian[3] species on the adjacent coast of

Africa, than to indicate the direct connection between the continent

and those islands within a geological period at all recent.’

Were this diversity due solely or chiefly to the Canaries wanting

many Maroccan plants, the inquiry would not be a pressing one;

but as to this deficiency is to be added the presence in the

Canaries of many indigenous species, and even several genera[4]

which are absent in Marocco, and in Marocco the great rarity of

endemic genera, of which _Argania_ only is arboreous, the inquiry

becomes a very important one, inviting a much closer study than

can here be given to it.

The Flora of the Canarian Archipelago, though consisting, like the

Maroccan, for the most part of Mediterranean species, yet differs

from that of Marocco, in containing many plants that may be classed

under the following categories:—

I. It contains many non-Maroccan plants, obviously introduced by man,

and not from Europe only, but from various parts of both the Old and

New Worlds. This will not appear surprising when it is remembered

that Teneriffe was for several centuries the Prime Meridian of

Geographers and the resort of all the European ocean-navigators,

who took their departure from it on their outward voyages, and made

for it on their homeward ones. The _Alternanthera achyrantha_, a

tropical American plant, was no doubt imported into the Canaries,

and possibly from thence introduced into Spain (where it is now

naturalised). _Argemone mexicana_ is another, and there are still

other as conspicuous examples of such foreign introductions. This

maritime intercourse can, however, only partially account for the

remarkable disproportion between the number of probably introduced

plants in the Canaries and in Marocco; and we must take into account

the isolation, barbarism, and exclusiveness of the latter country,

and the absence of any commercial intercourse between it and the

Canaries or the rest of the world.

In Webb and Berthelot’s ‘Phytographia Canariensis’ upwards

of fifty plants are enumerated as to which we have little doubt

that all have been introduced by man, and none of which have

hitherto been found in Marocco. The list includes many weeds of the

widest tropical and temperate distribution, as species of _Sida_,

_Waltheria_, _Siegesbeckia_, _Bidens_, _Lippia_, _Physalis_,

_Nicandra_, _Euphorbia_, _Alternanthera_, _Commelyna_, and various

_Cyperaceæ_, and Grasses.

II. The Canaries contain many apparently indigenous plants, which,

though not Maroccan, are widely distributed elsewhere; these form

a large class, and the following are some of the most prominent

of them:—

Delphinium Staphysagria | Fragaria vesca

Hypecoum procumbens | Pyrus Aria

Biscutella auriculata | Prunus lusitanica

Viola canina | Epilobium palustre

Silene Behen | Anthemis fœtida

„ nutans | „ coronopifolia

Rhus Coriaria | Cynara horrida

Spartium junceum | Lactuca sylvestris

Ulex europæus | Cressa cretica

Medicago arborea | Calamintha Nepeta

Trigonella hamosa | Atriplex glauca

Trifolium striatum | Euphorbia serrata

„ squarrosum | „ obliquata

„ suffocatum | „ Lagascæ

„ filiforme | Orchis longibracteata

Lotus angustissimus | Ophrys tabanifera

Vicia hirsuta | Iris pallida

Lathyrus odoratus | Lilium candidum

Alchemilla arvensis |

together with various _Cyperaceæ_, Grasses and water-plants, some of

which, and of the above, will no doubt hereafter be found in Marocco.

III. They contain some quite peculiar plants which are more

closely allied to endemic species of Marocco than to those of

any other country, and may have been derived from species that

originally were transported from that country. These are but few,

and are almost confined to species of the genus _Monanthes_, which

is limited to these countries and the Cape de Verde Islands, of

Cactoid _Euphorbiæ_, of succulent _Sonchi_, and of the _Kleinia_

division of _Senecio_.

IV. They contain plants not found hitherto in Marocco, and which are

more closely allied to Mediterranean species than to any others;

and these form a very large class. The data for a complete list

would require a very careful comparison of the Maroccan species

with the species described in the ‘Phytographia’ and discovered

since, many of which are unquestionably founded on too slight or

too variable characters.[5]

It will be sufficient for present purposes to contrast the results

obtained from a selection of genera[6] taken for comparison

from Ball’s ‘Spicilegium’ with the same from Webb’s

‘Phytographia’:—

+----------------------------+----------------+----------------+

| | Canary Islands | Marocco |

| +-------+--------+-------+--------+

| | of |confined| of |confined|

| |species| to |species| to |

+----------------------------+-------+--------+-------+--------+

|Hypericum | 8| 7| 7| 0|

|Matthiola | 4| 3| 3| 0|

|Cistus | 2| 1| 7| 0|

|Helianthemum | 6| 3| 14| 0|

|Polycarpia | 6| 4| 1| 0|

|Sempervivum | 23| 23| 1| 1|

|Cytisus | 11| 9| 11| 4|

|Lotus | 10| 6| 14| 2|

|Dorycnium | 3| 3| 1| 0|

|Rhamnus | 3| 3| 3| 0|

|Ilex | 2| 2| 0| 0|

|Chrysanthemum | 12| 12| 11| 4|

|Senecio | 9| 5| 11| 1|

|Doronicum | 5| 5| 0| 0|

|Tolpis | 5| 4| 2| 0|

|Sonchus | 17| 12| 6| 0|

|Convolvulus sect. Rhodorhiza| 5| 5| 0| 0|

|Echium | 12| 10| 9| 1|

|Micromeria[7] | 17| 17| 1| 0|

|Sideritis | 6| 5| 7| 2|

|Teucrium | 3| 1| 11| 4|

|Solanum | 6| 2| 2| 0|

|Scrophularia | 5| 3| 9| 1|

|Digitalis | 2| 2| 2| 0|

|Statice | 9| 9| 13| 3|

|Plantago | 10| 3| 11| 1|

|Beta | 3| 2| 1| 0|

|Euphorbia | 19| 9| 22| 6|

|Ephedra | 3| 2| 2| 0|

|Juniperus | 2| 1| 4| 0|

|Pinus | 1| 1| 1| 0|

|Ruscus | 2| 2| 1| 0|

|Asparagus | 5| 4| 6| 1|

|Scilla | 4| 4| 9| 0|

|Luzula | 3| 3| 1| 0|

| +-------+--------+-------+--------+

| | 243| 187=¾ | 204| 31=⅙ |

+----------------------------+-------+--------+-------+--------+

The disproportion between the two Floras in the case of these

selected genera is thus well shown. It is most remarkable; the number

of endemic species being in the Canaries three-fourths of the whole

and in Marocco only one-sixth; and were the peculiar genera of the

Canaries added, the disproportion would of course be increased.

The total number of Canarian species enumerated by Webb and Berthelot

is about 1,000, of which 367,[8] or more than one-third, are regarded

as peculiar to the Archipelago (a very few only of these being also

Madeiran); whereas out of 1,627 Maroccan species only 165, or a

little over one-tenth, are peculiar. Future discoveries will probably

not materially increase the Maroccan proportion of peculiar species;

whereas since the publication of Webb’s ‘Phytographia’ many

peculiar species (especially of _Statice_ and _Crassulaceæ_) have

been discovered in the Canaries, and but few species common to other

countries; and these additions will go far to neutralise any error

introduced into the estimate, due to the great number of new species

founded on insufficient data which the ‘Phytographia’ includes.

Under this head also should be included the peculiar Canarian genera

that appear to be modifications of continental ones. They are

_Bencomia_, closely allied to _Poterium_, of which there are two

species, both confined to one Island (Teneriffe); one of these is

also a native of Madeira, where only two individual trees, a male and

a female, have ever been seen! _Gesnouinia_, allied to _Parietaria_;

and _Canarina_, a monotypic genus allied to _Campanula_, but having a

baccate fruit. _Bosea_, also a monotypic plant, is wholly unlike any

known genus, and is, in some respects, intermediate between the two

very distinct natural families—_Chenopodiaceæ_ and _Phytolacceæ_.

V. Many Canarian plants are representatives of Floras more distant

than those of Marocco or Western Europe, and are not found in those

countries. These form an exceedingly interesting group, and may be

classed according to countries thus:—

_a. Oriental._—These are chiefly Arabo-Egyptian, but some of them

extend even into Western India, and a few are representatives of

tropical India. Some will no doubt yet be discovered in Marocco,

especially south of the Atlas; and it is not unreasonable to suppose

that such have crossed Africa in a subtropical latitude, and thus

reached the Canaries under conditions now operating.

The most remarkable are the following. The genera in capitals have

not hitherto been found in Marocco:—

Polycarpon succulentum | CAMPYLANTHUS salsoloides

VISNEA Moccanera | TRAGANUM nudatum

GYMNOSPORIA cassinoides | APOLLONIAS barbusana

Trigonella hamosa | Euphorbia Forskählii

Senecio flavus | DRACÆNA Draco

CEROPEGIA dichotoma |

Of the above hardly any have been found west of the Levant, or

anywhere between Egypt and the Canaries, except, possibly, in

Southern Algeria. _Traganum_ must be reckoned as an African and

Oriental desert type, and will probably be found in South Marocco;

but _Ceropegia_ is mainly Indian, as is _Gymnosporia_ (_Catha

cassinoides_, Webb). _Campylanthus_ consists of the Canarian species,

of a variety or closely allied one in the Cape de Verde Islands,

and of a third which extends from Southern Arabia to Scinde. The

nearest ally of the _Apollonias_ (_Phœbe barbusana_, Webb) is a

Ceylon tree; and _Visnea_ is nearly allied to the Malayan genus

_Anneslea_. _Dracæna Draco_ is the most interesting of all in the

list; for, though the genus abounds in tropical Africa, the Canarian

form, which is also a native of the mountains of the Cape de Verde

Islands, has only one near ally, the _D. Ombet_, which is confined

to Abyssinia, Southern Arabia, and the intervening Island of Socotra.

_b._ The peculiar species representing American types inhabiting

the Canaries or Madeira, but not found in Marocco, are in some

respects even more remarkable than the Oriental.

They belong to the following genera:—

_Bowlesia_[9] (_Drusa oppositifolia_, DC.), _Clethra_, five

species of _Bystropogon_, and _Cedronella_. Of these _Bowlesia_

is otherwise confined to the tropical Andes of America, one species

only extending as far north as Mexico; the Canarian species, which

according to Webb is found on rocky shaded places in Teneriffe,

from the sea-level to the wooded region, is most closely allied

to a Peruvian one. _Clethra_ is a genus which extends from South

Brazil to the Northern United States, and is also found in Japan and

the Malayan Archipelago. The Macaronesian species most resembles a

North American; it is found also in Madeira. _Bystropogon_ is, like

_Bowlesia_, an Andean genus, extending from Peru to Columbia. All the

Canarian species belong to a different section from the Andean, and

there is one species of the same section in Madeira. _Cedronella_ is

a North American and Mexican genus, and the Canarian species differs

from all its congeners in its trisect leaves; it is also Madeiran.

Of the Canarian _Laurineæ_, _Persea indica_, also a native of

Madeira and the Azores, belongs to an American section of that

large genus.

_c._ Tropical and South African types in the Canaries. Of these the

most noticeable are two forest trees, belonging to the large tropical

genus _Myrsine_. One of these, _M. excelsa_ (_Heberdenia excelsa_,

Banks) is also found in Madeira; the other, _M. canariensis_,

is confined to the island whose name it bears. The tropical order

_Sapotaceæ_, to which _Argania_ belongs, has no representative in

the Canaries, but has one in the _Sideroxylon Mermulana_ of Madeira.

The only almost exclusively South African genus[10] in the Canaries

is a species of _Lyperia_, of which there are numerous Cape of Good

Hope species, and one doubtful one in the Somali country (North-East

Africa). The widely diffused Cape shrub, _Myrsine africana_, is

found in the Azores and in Abyssinia, but not in the Canaries, Cape

de Verdes, Madeira, or Marocco. The two singular shrubs _Phyllis_

and _Plocama_, consisting each of a single species, of which the

_Phyllis_ is found also in Madeira, are representatives of the

_Anthospermeæ_, a very large and conspicuously South African and

Australian tribe of _Rubiaceæ_, and of which the only Maroccan

representative is _Putoria_, a Mediterranean genus of a single

species, and which is not Canarian.

The _Oreodaphne fœtens_ of the Canaries and Maderia is now[11]

referred to the American, Madagascar, and South African genus

_Ocotea_, and is most nearly allied to a species found in the

latter country.

The Maroccan flowering plants are thus grouped by Ball in his

‘Spicilegium Maroccanum’[12]:—

Total number of Maroccan species 1,627

Species widely diffused, temperate or tropical 467

Of which there are common to Marocco and the Islands 300

Maroccan, but not Insular 167

Mediterranean species in Marocco 995

Of which there are widely spread species common to the 254

Islands and Marocco

Confined to Marocco and the Islands 15

Mediterranean species in Marocco, but not in the 726

Islands

Maroccan species exclusively 165

The proportion of _Monocotyledons_ to _Dicotyledons_ is in Marocco

1 to 4·6, in the Canaries 1 to 6—a very great difference.

The leading natural orders in Marocco and the Canaries respectively

are:—

Marocco Canaries

Species Species

Compositæ 208 143

Leguminosæ 189 104

Gramineæ 134 77

Umbelliferæ 86 27

Labiatæ 81 59

Cruciferæ 73 29

Caryophylleæ 69 38

In each country these seven natural orders include nearly half the

Dicotyledonous plants. But in the Canaries the _Crassulaceæ_ with

31 species should replace the _Cruciferæ_, and the _Umbelliferæ_

be excluded.

The natural orders which are indigenous to the three Archipelagos

of the Canaries, Madeira, and the Azores, but which are absent in

Marocco, and the reverse are:—

In the Archipelago, but not | In Marocco, but not in the

in Marocco. | Archipelago.

Simarubeæ (Cneorum) | Berberideæ

Pittosporeæ | Capparideæ

Ternstrœmiaceæ | Polygaleæ

Ilicineæ | Ampelideæ

Myrsineæ | Coriarieæ

Phytolacceæ (Bosea) | Saxifrageæ

Myriceæ | Apocyneæ

Commelyneæ (introduced?) | Lentibularieæ

| Nyctagineæ

| Ulmaceæ

| Cupuliferæ

| Ceratophylleæ

| Alismaceæ

| Juncagineæ

| Melanthaceæ

In the above lists the _Commelyneæ_ are most probably introduced

by man into the Canaries, and the absence of _Lentibularineæ_,

_Ceratophylleæ_, _Alismaceæ_, and _Juncagineæ_ in the Archipelago

may be due to the want of suitable localities. The total absence of

_Cupuliferæ_ in all the Macaronesian Archipelago is inexplicable;

and of _Quercus_ especially, a genus so prominently developed in

number of species and individuals on both continents, and which

further abounds in both the Pliocene and Miocene beds of Europe.

The apparently indigenous Macaronesian genera which are wanting in

Marocco are the following. Those in capitals are confined to the

Canaries, or to the Canaries and Madeira:—

Malvaceæ

Abutilon

Cruciferæ

PAROLINIA

Barbarea

Simarubeæ

Cneorum

Celastrineæ

Gymnosporia

Sapindaceæ

Melianthus?

Leguminosæ

Spartium

Ulex

Rosaceæ

BENCOMIA

Alchemilla

Fragaria

Aquifoliaceæ

Ilex

Pittosporeæ

Pittosporum

Ternstrœmiaceæ

VISNEA

Umbelliferæ

Todaroa

Rubiaceæ

PHYLLIS

PLOCAMA

Compositæ

Chrysocoma

Allagopappus

Vieræa

Doronicum

Serratula

Prenanthes

Campanulaceæ

MUSSCHIA

CANARINA

Wahlenbergia

Ericeæ

Clethra

Asclepiadeæ

Ceropegia

Convolvulaceæ

Cressa

Boragineæ

Tournefortia

Labiatæ

Bystropogon

Cedronella

Verbenaceæ

Lippia

Solaneæ

Nicandra

Scrophularineæ

Campylanthus

Lyperia

Acanthaceæ

Justicia

Oleineæ

Notelæa

Myrsineæ

Myrsine

Sapotaceæ

Sideroxylon

Primulaceæ

Pelletiera

Chenopodieæ

Traganum

Laurineæ

Persea

Apollonias

Ocotea

Phytolacceæ

BOSEA

Urticeæ

GESNOUINIA

Myriceæ

Myrica

Aroideæ

Dracunculus

Liliaceæ

Dracæna

Cyperaceæ

Fimbristylis

Cladium

Gramineæ

Chloris

Tricholæna

There are in Marocco, out of a total of 517 genera, 202, included

under 67 orders, that have no indigenous species in the Canaries

or Madeira. Many of these, about a quarter, being North Maroccan,

_i.e._ only found in parts of Marocco farthest from the Canaries,

would not be expected to occur in those islands, were it not that the

vegetation of islands near to large continents often most resembles

that of a higher latitude on the continent than that in which the

islands are situated.

The following is a list of the Maroccan genera which are absent

in Macaronesia;—those confined to North Marocco marked *; those

which have been found in Macaronesia, but certainly introduced,

marked ‖; those in italics have been discovered since our return

from Marocco.[13]

Clematis

Thalictrum

*Anemone

_Aconitum_

Berberis

Rœmeria

Corydalis

Cardamine

_Morettia_

_Anastatica_

Draba

*Erophila

Malcolmia

Diplotaxis

_Moricandia_

‖Lepidium

Thlaspi

Iberis

Hutchinsia

Isatis

Ceratocnemum

*Cakile

*Hemicrambe

_Cleome_

Capparis

_Caylusea_

Fumana

Polygala

Velezia

Dianthus

Holosteum

Buffonia

Lœfflingia

Montia

Althæa

Malope

*Radiola

Peganum

Celastrus

Zizyphus

Acer

*Coriaria

Lotononis

_Crotalaria_

Argyrolobium

*Calycotome

Anthyllis

*Securigera

Coronilla

Colutea

*Glycyrhiza

Hedysarum

Ornithopus

Ebenus

*Pisum

Ceratonia

‖Acacia

Saxifraga

_Parnassia_

Ribes

*Drosophyllum

*Peplis

*Ecbalium

*Hydrocotyle

Eryngium

Deverra

Hippomarathrum

Kundmannia

*Magydaris

Sclerosciadium

Meum

Heracleum

*Peucedanum

‖*Coriandrum?

Thapsia

Elæoselinum

_Gaillonia_

Putoria

Callipeltis

Asperula

Crucianella

*Valeriana

‖Centranthus

*Fedia

Nidorella

Nolletia

Micropus

Leysera

_Grantia_

_Anvillea_

*‖Xanthium

Achillea

Cladanthus

Echinops

Xeranthemum

Onopordon

Stæhelina

Crupina

*Leuzea

Carduncellus

Catananche

Hyoseris

Phœcasium

Hieracium

Scorzonera

Jasione

Trachelium

*Calluna

Armeria

Limoniastrum

Plumbago

Coris

Argania

Fraxinus

Phyllyrea

*Vinca

Nerium

_Dæmia_

_Glossonema_

Boucerosia

*Microcala

Cicendia

_Trichodesma_

Echinospermum

Rochelia

Nonnea

Cerinthe

Calystegia

*Mandragora

Anarrhinum

*Pinguicula

‖*Acanthus

Vitex

Lycopus

*Satureja

Hyssopus

Cleonia

Zizyphora

*Betonica

Ballota

Boerhavia

Corrigiola

Scleranthus

_Sclerocephalus_

Polycnemum

_Telephium_

*Obione

Salicornia

Caroxylon

Passerina

Osyris

Andrachne

*Ulmus?

Celtis

Quercus

Populus

Ceratophyllum

Callitris

Cedrus

Aceras

*Serapias

*Cephalanthera

*Crocus

Leucojum

*Lapiedra

*Tapeinanthus

*Corbularia

Narcissus

Aurelia

*Alisma

Damasonium

*Triglochin

Chamærops

Gagea

*Hyacinthus

Anthericum

*Simethis

*Aphyllanthes

Colchicum

Erythrostictus

*Convallaria

*Schœnus

*Leersia

Lygeum

*Crypsis

*Alopecurus

Macrochloa

*Sporobolus

Ammophila

‖Arundo

*Ampelodesmos

Phragmites

_Pappophorum_

Echinaria

*Spartina

*Airopsis

Gaudinia

Glyceria

Secale

Elymus

*Lepturus

Anthistiria

These 202 genera, which are absent in the Canaries, comprise upwards

of 300 Maroccan species, including _Eryngium_, with eleven species,

_Coronilla_ with eight, _Diplotaxis_ with seven, _Narcissus_,

_Anthyllis_, _Polygala_, _Passerina_, and _Quercus_ five each,

besides twenty other genera with three or four each. Not a few of

them contain very common and wide-spread species, as do all the

above-named, as well as _Clematis_, _Malcolmia_, _Cardamine_,

_Dianthus_, _Hedysarum_, _Heracleum_, _Asperula_, _Achillea_,

_Onopordon_, _Hyoseris_, _Scorzonera_, _Phyllyrea_, _Fraxinus_,

_Calystegia_, _Anarrhinum_, _Ballota_, _Populus_, _Chamærops_. That

no species of these or of many of the other genera should exist in

the Canaries is inexplicable, considering the position and extent

of the Archipelago, and the means of migration which must exist

between it and the mainland.

The species common to Macaronesia and Marocco exclusively, are in

so far as is at present known:—

Helianthemum canariense, _Jacq._

Polycarpia nivea, _Ait._ (also occurs in C. de Verde)

Zygophyllum Fontanesii, _Webb_

?Cytisus albidus, _DC._

Ononis angustissima, _Lam._ (?A form of _0. Natrix_)

Astragalus Solandri, _Lowe_ (Madeira only)

Astydamia canariensis, _DC._

Bowlesia oppositifolia

Odontospermum odorum, _Schousb._

Sonchus acidus, _Schousb._ (In Lancerotte, only a single plant,

possibly introduced)

Lithospermum microspermum, _Boiss._

Linaria sagittata, _Poir._

Chenolea canariensis, _Moq._

Salix canariensis, _Chr. Sm._ (rather uncertain)

Romulea grandiscapa, _Webb._ (Perhaps only a var., but Baker keeps

it)

Asparagus scoparius, _Lowe._ (Not quite certain)

Although it would be out of place here to discuss all the questions

raised by this slight sketch of the peculiarities of the Canarian

Flora, there are some of them which so intimately bear upon the

Maroccan as to awaken attention.

The wonderful development in the Canaries of endemic species

belonging for the most part to Mediterranean types, points to the

very early introduction of the parent forms of these, and the long

isolation both of the Archipelago and its separate islets. It is

in accordance with generally accepted views, to assume that the

endemic species of each genus have been derived from parent forms

originally introduced into one or more of the islets; and that as

the descendants of these species spread over the Archipelago they

were exposed to different conditions in each islet, resulting in

their varying, and in the segregation and conservation of different

local varieties each in its own insular birth-place; a supposition

which is in accordance with the fact that those endemic species

are really very local, many being confined to a single islet. In

Marocco the parent forms of its Flora would be exposed to no such

diverse conditions, and the areas in which varieties occurred,

not being isolated, would be exposed both to invasion on all sides

by other plants, and to destruction by agencies that affected the

whole surrounding country, as drought, floods, insects, and birds.

The tropical types in the Canaries, with the exception of the

Egypto-Arabian and the trees mentioned under V. _c._, are chiefly

weeds of wide distribution, which have not reached Marocco, because

of its want of ports and its limited commerce.

Finally the _Dracæna_, together with the tropical trees of

_Myrsineæ_, _Sapotaceæ_ (in Madeira), and _Laurineæ_, and the

Egypto-Arabian types, suggest the hypothesis that at a very remote

period these and many other plants of warmer and damper regions

flourished in the area included in North-West Africa and its adjacent

islands, and that they have been expelled from the continent by

altered conditions of climate, but have been preserved in the more

equable climate and more protected area of the Atlantic Islands.

Ball, who has given me valuable aid on many points discussed in this

article, directs my attention to the important differences that

exist between the vegetation of the eastern group of the Canary

Islands—Fuertaventura, Lanzarote, and the adjacent islets—the

‘Purpurariæ’ of authors, and the western group, including

Teneriffe, Grand Canary, &c.

In the first place, nearly all the characteristic Canarian types

are absent in the eastern group. Out of fifty-four genera above

enumerated as present in the Canaries but wanting in Marocco, two

are in the Canaries confined to the eastern islands: one of these,

_Traganum_, is an African desert type, probably to be found in

South Marocco; the other, _Melianthus_, a Southern African plant,

and scarcely indigenous. Of the remainder _Plocama_ alone is

certainly present, and three other generic types probably exist in

that group; while forty-eight genera, including eight out of nine

peculiar to the Canaries, are apparently absent. In the next place

several characteristic desert plants, such as _Oligomeris subulata_,

_Ononis vaginalis_, _Convolvulus Hystrix_, and _Traganum nudatum_,

are present in the ‘Purpurariæ,’ but absent from the western

islands.

Although the Flora of the Purpurariæ is incompletely known, and

our acquaintance with that of the neighbouring African coast between

the rivers Sous and Draha is extremely imperfect, these facts tend

to prove that there is a closer botanical relationship between the

eastern islands and the adjoining continent than there is between

them and the western portion of the Canarian Archipelago. Such

relationship might be brought about in three different ways.

1. The greater dryness and heat of the eastern islands may have

favoured the immigration of African forms, and at the same time

led to the destruction, or weeding out, of the characteristic

Canarian types. In this case the cause would be of a purely local

and climatic character.

2. We may believe in the trans-oceanic migration of some African

species to the nearer islands, along with the transport of some

Canarian species (those enumerated in p. 416, and others which may

be hereafter found) to the neighbouring continent.

3. An ancient extension of the continent to the Purpurariæ,

leaving the other islands separated by deep sea.

It is an objection to the latter hypothesis that a profoundly deep

ocean bed lies between the lines of 100 fathom soundings that girdle

the islands and the African coast respectively; and that while the

100 fathom line extends about thirty miles from the coast of the

continent, it is never more than five miles, rarely more than one

or two, from those of the islands.

In favour of the hypothesis of trans-oceanic transport it may

be remarked that the distance between the African coast and

Fuertaventura is not more than seventy miles, and that a moderate

change of level of about 600 feet would reduce that distance by

one-half, while it would but slightly affect the interval that

separates the Purpurariæ from the other islands.

Among the possible causes leading to an interchange of species

between the Purpurariæ and the African coast the agency of man

must not be omitted. The fishermen of those islands were formerly

in the habit of visiting some points on the opposite coast, although

intercourse of this kind has almost ceased in recent times.

It must be observed that our knowledge of the vegetation of the

Canary Islands is yet incomplete. Although several additions to the

Flora have been published by C. Bolle and others, no supplement to

Webb’s ‘Phytographia’ has been published. Several additional

species exist in herbaria, besides those that may be hereafter found.

So little is known of the geology of Marocco, that there are no

data for ascertaining whether during antecedent geological periods

it contained a more tropical Flora than now; but evidence in support

of such a hypothesis is forthcoming in Madeira, where fossiliferous

beds which have been referred to ‘some part of the Pliocene

period’[14] have been discovered, containing leaves referable

in part to existing species of Madeiran plants, and in part to

extinct ones of tropical aspect;[15] and it is well ascertained

that during preceding geological periods Western Europe was clothed

with a vegetation that suggests a very much warmer climate than

now prevails, and of which vegetation the _Laurus nobilis_ in the

south-west of the continent has been supposed to be a surviving

representative.

In Grand Canary, also, Upper Miocene beds exist, containing numerous

species of fossil shells, of which one is an Oregon species, and

another tropical African; and in more recent deposits of the same

Archipelago many shells have been found which no longer inhabit

the adjacent seas, including tropical West African, Mozambique,

and Mediterranean species.

We can form no conception of means of transport from the American

continent that would transfer the parent species of _Bowlesia_ and

of the _Bystropogons_ from the Andes to the Atlantic islands; and we

can but hazard the assumption that, at some very distant date, these

genera existed in more eastern parts of America, from whence seeds

were transported across the ocean. On the other hand, the transport

of parent forms or existing species from the continents of Europe

and Africa to the Atlantic islands may have been much facilitated by

greater extensions of land in bygone ages. Madeira, the Canaries,

and the Cape de Verde Islands, are all supposed to stand on a

submarine platform which skirts the coasts of Western Europe and

North-Western Africa, and whose submerged margin immediately to

the westward of the position of the islands descends rapidly to a

profound depth. The westward margin of this platform was possibly

the coast-line in Miocene times. An elevation of its surface of

a few hundred feet would approximate the islands to the mainland

very materially, and greatly facilitate transport. That they were,

however, ever united to the continent is opposed to the views of most

competent geologists. Lyell, speaking of this, says: ‘The general

abruptness of the cliffs of all the Atlantic islands, coupled with

the rapid deepening of the sea outside the 100 fathom line, are

characters which favour the opinion that each island was formed

separately by igneous eruptions, and in a sea of great depth.’

Moreover, the Azores, whose botany in so many respects resembles

that of the other Atlantic islands, as distinguished from that of

the continent, are enormously more distant from the mainland; and

these islands stand on a platform of their own, separated from the

continental one by an ocean of profound depth; so that any theory of

transport which applies to the Canarian and Madeiran Archipelagos,

should apply also to the Azorean.

It remains a point of some nicety to decide whether the Macaronesian

islands should be regarded as a Botanical province apart from the

Mediterranean, or a sub-division of the latter. The assemblage of

American and Oriental genera which their Flora contains, together

with the arboreous representatives of tropical _Laurineæ_, all so

entirely foreign to the European Flora, would give it a title to be

called a Botanical province; and to this as a further title is the

prevalence of a considerable proportion of North European plants,

in the Northern Archipelago especially. On the other hand, fully

two-thirds of the species are typical of the Mediterranean Flora, and

by far the majority of the remainder are derivative species of the

same origin; so that, on the whole, I am disposed to regard it as a

very distinct sub-division of the Mediterranean province, which owes

its peculiarities partly to the conservation of types once common

to West Europe and North Africa, but which have been eliminated in

those regions, and partly to the effect of isolation and climate

on the progeny of species still existing in those regions.

FOOTNOTES:

[Footnote 1: The Canary Islands are situated about 3° farther

south, and 280 miles distant from Mogador. They are thus opposite

a much more hot and arid part of the African coast than that north

of the Atlas. The large island of Fuertaventura is only about 70

miles from the continent south of Oued Noun.]

[Footnote 2: _Journ. Linn. Soc._ vol. xvi. p. 297.]

[Footnote 3: A term first applied by Webb to the Flora of the

Canarian Archipelago, but which should also include the Flora of

Madeira (as Ball makes it do in the above mention of it), the Azores,

and perhaps also of the Cape de Verde Islands, which together form

either a distinct botanical province, or a marked subdivision of

the Mediterranean province.]

[Footnote 4: No less than nine very distinct genera are confined

to the Canaries or Madeira or both:—_Parolinia_, _Bencomia_,

_Visnea_, _Phyllis_, _Plocama_, _Canarina_, _Musschia_, _Bosea_,

and _Gesnouinia_. The only endemic genera in Marocco are _Argania_,

_Hemicrambe_, _Ceratocnemum_, and _Sclerosciadium_.]

[Footnote 5: On the other hand, many peculiar species have been

added to the Canarian Flora since the date of the publication of

the _Phytographia_ (1836-50).]

[Footnote 6: The genera, which are unduly multiplied in the

_Phytographia_, are here reduced to the standard adopted in the

_Spicilegium_. The species are, unfortunately, also inordinately

multiplied in the former work, which seriously vitiates the table:

this, however, it is impossible to set right. On the other hand,

some of the Canarian genera have been largely added to by later

explorers.]

[Footnote 7: In this, the most curious case of all, the species

were elaborated by Bentham, and may, therefore, be depended upon. A

second Maroccan _Micromeria_, allied to a Canarian one, has been

found by M. Cosson’s collectors, as I am informed by Ball, whilst

this sheet was passing through the press.]

[Footnote 8: This estimate is subject to the same deductions as I

have referred to in note 2, p. 407. On the other hand, were the

many obviously introduced species to be struck out of Webb and

Berthelot’s enumeration, the proportion of peculiar species would

be considerably augmented.]

[Footnote 9: Whilst this sheet was passing through the press,

I am informed that M. Cosson’s collectors have found _Bowlesia_

in South Marocco. No doubt this is another case of that accidental

diffusion of Macaronesian species alluded to by Ball. (See p. 405.)]

[Footnote 10: The Cape of Good Hope mountain plant, _Melianthus

comosus_, found at the south end of Fuertaventura, must be assumed

to have been introduced by man into that island.]

[Footnote 11: In Bentham and Hook, f., _Gen. Plant._

(vol. iii. ined.), the _Laurineæ_ are described by Bentham, who

has determined, for the first time, the proper position of the

Canarian Laurels.]

[Footnote 12: _Journ. Linn. Soc. Bot._ vol. xvi.]

[Footnote 13: M. Cosson has published in the 22nd volume of the

‘Bulletin of the Botanical Society of France’ a list including

the plants received from his collectors in South Marocco up to the

year 1874.]

[Footnote 14: Lyell’s _Principles of Geology_, ed. 11,

vol. ii. p. 410.]

[Footnote 15: Lyell’s _Student’s Elements of Geology_, ed. 2,

pp. 538, 539.]

* * * * *

APPENDIX F.

_Comparison of the Maroccan Flora with that of the Mountains of

Tropical Africa._

By JOSEPH DALTON HOOKER.

As was to have been anticipated, the Maroccan Flora contains most of

the European species which have been collected on the mountains of

Abyssinia and of the Bight of Biafra, which alone of the tropical

African Alps have been botanically explored. Of these the former

have been visited by Schimper and various collectors; whilst the

mountains of the pestilential West African coast, of Fernando Po,

9,500 feet, and the Cameroons Mountains, upwards of 13,000 feet,

have been ascended for botanical purposes only by Gustav Mann,

when employed for the Royal Gardens of Kew.

The results of the latter were published by myself in the ‘Journal

of the Linnæan Society of London’ (vol. vii. p. 171), from whence

the following observations are for the most part extracted. They

included 26 European species, gathered at elevations between 5,000

and 10,000 feet. Most of them are also natives of the Abyssinian

Alps, and two-thirds of them are also Maroccan, whilst others will

probably yet be found in the latter country.

The following is a catalogue of all the European plants found in

the upper regions of the Cameroons Mountains and Fernando Po:—

+-----------------------+--------------+-----------------------+

| | Height | Where found |

| +--------------+-----------------------+

| | feet | |

|Cardamine hirsuta | 7,000-10,000 | Marocco and Abyssinia |

| | | |

|Cerastium vulgatum | 8,000 | „ „ |

|(viscosum Fr.) | | |

| | | |

|Radiola Millegrana | 7,000 | Marocco |

| | | |

|Oxalis corniculata | 7,000-8,500 | Marocco and Abyssinia |

| | | |

|Umbilicus pendulinus | 7,000-10,000 | „ „ |

| | | |

|Sanicula europæa | 4,000-7,500 | Abyssinia |

| | | |

|Galium rotundifolium | 7,000-12,000 | Marocco and Abyssinia |

| | | |

|Galium Aparine | 7,000-10,000 | Marocco and Abyssinia |

| | | |

|Scabiosa succisa | 10,500? | |

| | | |

|Myosotis stricta | 8,000-10,000 | Marocco and Abyssinia |

| | | |

|Limosella aquatica | 9,000-10,000 | Abyssinia |

| | | |

|Sibthorpia europæa | 7,000-7,500 | „ |

| | | |

|Solanum nigrum | 7,000-11,000 | Marocco and Abyssinia |

| | | |

|Rumex obtusifolius | 7,000 | Abyssinia |

| | | |

|Parietaria mauritanica | 7,000-8,000 | Marocco and Abyssinia |

| | | |

|Trichonema Bulbocodium | 7,000-9,000 | „ „ |

| | | |

|Juncus capitatus | 7,000 | Marocco |

| | | |

|Luzula campestris | 8,000-10,000 | Abyssinia |

| | | |

|Deschampsia cæspitosa | 9,000-12,000 | „ |

| | | |

|Aira caryophyllea | 7,000-8,000 | Marocco and Abyssinia |

| | | |

|Poa nemoralis | 7,000-10,000 | Abyssinia |

| | | |

|Kœleria cristata | 8,000-12,000 | „ |

| | | |

|Vulpia bromoides | 7,000-10,000 | Marocco and Abyssinia |

| | | |

|Festuca gigantea | 8,500 | Marocco |

| | | |

|Brachypodium sylvaticum| 7,000 | Abyssinia |

| | | |

|Andropogon distachyus | 7,000 | Marocco and Abyssinia |

+-----------------------+--------------+-----------------------+

The most remarkable features of the Temperate vegetation of these

West African tropical mountains are:—

1. Its poverty.

2. The preponderance of Abyssinian genera and species.

3. The considerable proportion of European plants.

4. The paucity of South African genera and species.

5. The great rarity of new genera.

6. The absence of St. Helena and Canarian types.

Upon each of these propositions I have a few general remarks

to offer.

In the poverty of their Flora the Cameroons range and Peak of

Fernando Po seem to partake of the characteristics of the Abyssinian

Alps. We know far too little of the physical geography of either of

these districts to hazard many conjectures upon this point, which

must to a certain extent be dependent on the arid volcanic nature

of the soil and the limited area of the Temperate region. Mr. Mann

spent many weeks, and at various seasons, in his explorations, and

yet 237 flowering plants were all that rewarded his toil. Geological

causes have probably had, in the case of the Cameroons Mountains,

much to do with the dearth of species, some parts of the range even

now presenting evidence of subterranean heat.

The preponderance of Abyssinian forms is proved by almost all of

the genera and half the species being natives of Abyssinia, and

by many other species being very closely related to, or obvious

representatives of, plants of that country. There are, further,

several of the genera and many of the species peculiar to Abyssinia

and the peaks of Biafra.

The number of European genera amounts to 43, and species to 26,

the greater part of which are British. Very few of them extend

into South Africa. The greater part are Abyssinian; the remarkable

exceptions being _Radiola_, _Scabiosa succisa_, _Luzula campestris_,

and _Festuca gigantea_, all of which, however, may have been hitherto

overlooked in Abyssinia.

I find no other evidence of relationship between the Biafran mountain

Flora and that of Marocco than what is afforded by the European

species common to both. In most other respects the Floras differ

totally, the other mountain plants of Biafra being Abyssinian or

Cape types, or more nearly related to tropical African ones.

* * * * *

APPENDIX G

_On the Mountain Flora of Two Valleys in the Great Atlas of Marocco._

By JOHN BALL.

Although an attempt to discuss the character and relations of the

Flora of a region so wide and so little known as the mountain region

of the Great Atlas would as yet be quite premature, it appears that

the materials at our disposal suffice for an examination of the

vegetation of the valleys lying south and south-west of the city

of Marocco, which may be an acceptable contribution to botanical

geography. For this purpose it seems best to limit the discussion to

the two valleys where our collections were sufficiently extensive

to give a tolerably complete representation of the vegetation,

as far as this was developed at the season of our visit, and to

exclude altogether the plants found along the skirts of the great

range below the level of about 1,200 metres above the sea. The Flora

of the zone below that level is largely mixed up with extraneous

elements, represented by plants of the low country that reach the

base of the mountains, but do not penetrate the interior valleys,

and if these had been admitted the special features of the mountain

Flora would have become less apparent. The plants collected in the

course of a somewhat hurried excursion from Seksaoua, when we reached

a height of about 1,600 metres, have been designedly omitted. On

such occasions attention is to a great extent monopolised by the

new and rare species not hitherto seen in the same region, while

comparatively familiar forms are less carefully noted. Collections

made under such circumstances rarely give a moderately complete

report of the vegetable population.

In ascending to the higher region of mountains that approach to

the limit of vegetation the absolute number of species is so much

smaller that this source of error is far less apparent; and it is

not likely that in the two ascents which we made to the dividing

ridge of the Atlas many species that came within our range of vision

were overlooked. The following tabular arrangement shows that in

the Aït Mesan valley, where we spent the greater part of six days,

we collected 375 species of phænogamous plants, to which have been

added three subsequently found there by MM. Rein and Fritsch; while

in the Amsmiz valley only 223 species—or less than three-fifths of

the above number—were collected. Of these 146 species are common

to both valleys; so that our list does not in all exceed 455 species

of flowering plants, to which I have added 10 vascular cryptogams,

of which two only were found in the Amsmiz valley.

In the following list I distinguish a middle zone, extending from

1,200 to 2,000 metres above the sea, and a superior zone including

all above that limit; the latter corresponding pretty nearly with the

sub-alpine and alpine zones of the higher mountains of Europe. With

reference to their distribution I have divided the species into four

categories: 1, Mid-European, those extending to Central Europe,

of which more than three-fourths belong to the British Flora: 2,

wide-spread Mediterranean, extending beyond the bounds of the three

adjoining regions, Algeria, the Spanish peninsula, and the Canary

Islands: 3, confined to adjoining regions; that is, to one or more

of those just enumerated: 4, endemic, known only in the Great Atlas,

or the neighbouring provinces of Marocco.

_Tabular View of the Mountain Flora of the Great Atlas, showing the

distribution of the Species found in the Valleys of Aït Mesan and

Amsmiz. S indicates the superior zone from 2,000 m. to 3,500 m. above

the sea; M the middle (or mountain) zone, from 1,200 m. to 2,000 m._

[A: Aït Mesan

B: Amsmiz

C: Mid-European

D: Wide-spread Mediterranean

E: Confined to adjoining regions

F: Endemic]

+----------------------------------------+---+---+---+---+---+---+

| Name of Species | A | B | C | D | E | F |

+----------------------------------------+---+---+---+---+---+---+

|Ranunculus spicatus, L. var. | — | S | — | — | * | — |

| „ atlanticus, Ball | M | M | — | — | | * |

| „ bulbosus, L. var. | M | M | * | — | — | |

| „ arvensis, L. |M S| — | * | — | — | |

| „ muricatus, L. | — | M | — | * | — | — |

| „ Reinii, nov. sp. | S | — | — | — | — | * |

|Aquilegia vulgaris, L. var. | — | M | * | — | — | — |

|Delphinium Balansæ, B. et R. var.? | S | S | — | — | * | — |

|Berberis cretica, L. var. | — | S | — | * | — | — |

|Papaver tenue, Ball |M S|M S| — | — | — | * |

| „ rupifragum, B. et R. var. | S | S | — | — | * | — |

|Rœmeria hybrida, D.C. | — | M | — | * | — | — |

|Hypecoum pendulum, L. | | M | — | * | | — |

|Corydalis heterocarpa (Dur.) | M | — | — | — | * | |

|Fumaria officinalis, L. | S | — | * | — | — | — |

| „ parviflora, Lam. | M | M | * | — | — | — |

| „ media, Lois var. | M | — | * | — | — | — |

| „ agraria, Lag. var. | M | — | — | * | — | — |

| „ tenuisecta, Ball. | M | — | — | — | — | * |

|Nasturtium officinale, R. Br. | S | — | * | — | — | — |

| „ atlanticum, Ball | S | — | — | — | — | * |

|Arabis albida, Stev. | S | — | — | * | — | — |

| „ erubescens, Ball | S | | | — | — | * |

| „ auriculata, Lam. | S | S | * | — | — | — |

| „ decumbens, Ball | S | S | | — | — | * |

| „ conringioides, Ball | S | S | | | — | * |

|Cardamine hirsuta, L. var. | — | S | * | | — | — |

|Alyssum alpestre, L. vars. | M | M | * | | | — |

| „ montanum, L. var. | | S | * | — | | — |

| „ campestre, L. |M S| — | * | — | | |

| „ calycinum, L. |M S| — | * | — | — | |

| „ spinosum, L. | S | — | — | * | — | |

|Draba hispanica, Boiss. | — | S | — | — | * | |

|Sisymbrium Thalianum | | S | * | — | — | |

| „ runcinatum, Lag. var. | — | M | — | — | * | |

|Erysimum australe, Gay, var, |M S|M S| * | — | — | — |

|Brassica rerayensis, Ball | S | — | — | — | | * |

|Capsella bursa-pastoris, L. | S | — | * | — | — | — |

|Lepidium nebrodense, Raf. var. | S | | — | * | — | |

|Biscutella lyrata, L. var. | S | — | — | * | — | — |

|Thlaspi perfoliatum, L. et var. | S | S | * | | — | — |

|Hutchinsia petræa, R. Br. | S | S | * | | — | — |

|Isatis tinctoria, L. var. | M | M | * | — | | — |

|Crambe hispanica, L. | — | M | — | | * | — |

|Capparis spinosa, L. | M | — | — | * | | — |

|Reseda attenuata, Ball | S | — | — | | | * |

| „ phyteuma, L. | | M | * | — | | — |

| „ lanceolata, Lag. | M | — | — | | * | |

|Cistus polymorphus, Willd. | M | — | — | * | | |

|Helianthemum niloticum, L. var.? | S | — | — | * | — | |

| „ rubellum, Presl. | — | M | | * | — | |

| „ glaucum, Cav. | — | M | | * | — | |

| „ virgatum, Desf. et var. | M | M | — | — | * | |

|Fumana glutinosa, L. | M | M | — | * | — | — |

| „ calycina, Claus. | M | — | — | — | * | — |

|Viola tezensis, Ball | — | S | — | — | — | * |

|Polygala rupestris, Pourr. | M | M | — | * | | — |

| „ Balansæ, Coss. | M | M | — | — | — | * |

|Dianthus attenuatus, Sm. |M S| | — | — | * | — |

| „ virgineus, L. | M | M | * | — | — | — |

|Tunica compressa, Desf. | — | M | — | — | * | — |

| „ prolifera, L. | M |M S| * | — | — | — |

|Silene inflata, Sm. var. | M | — | * | — | — | — |

| „ nocturna, L. | M | — | | * | — | — |

| „ corrugata, Ball | M | | — | — | — | * |

| „ muscipula, L. | M | | | * | — | — |

| „ italica, L. | M | M | | * | — | — |

|Holosteum umbellatum, L. | S | S | * | | — | — |

|Cerastium glomeratum, Thuill. | S | S | * | — | — | — |

| „ brachypetalum, Desf. | S | S | * | — | | — |

| „ arvense, L. |M S|M S| * | — | — | |

|Stellaria media, L. | M | — | * | — | — | |

| „ uliginosa, Murr. | S | — | * | — | — | |

|Arenaria pungens, Clem. et var. | S | S | — | — | * | |

| „ serpyllifolia, L. | S | S | * | — | — | |

| „ procumbens, Vahl. | M | | — | * | — | |

| „ fasciculata, Gouan | S | — | * | — | — | — |

| „ setacea, Thuill. var. | S | S | * | — | — | — |

| „ verna, L. var. | S | S | * | — | — | — |

|Buffonia tenuifolia, L. | M | — | — | * | — | — |

|Sagina procumbens, L. var. | S | S | * | | — | — |

| „ Linnæi, Prese. | S | — | * | — | | — |

|Polycarpon tetraphyllum, L. | | M | * | — | — | |

| „ Bivouæ, J. Gay | S | S | | * | — | |

|Montia fontana, L. | S | | * | — | — | — |

|Hypericum perforatum, L. | M | — | * | — | — | — |

| „ coadunatum, Chr. Sm. var. | M | — | — | — | * | — |

|Malva sylvestris, L. | M | — | * | | | — |

| „ rotundifolia, L. |M S| — | * | — | | — |

|Linum corymbiferum, Desf. | M | — | — | — | * | — |

|Fagonia cretica, L. | M | — | — | * | — | — |

|Geranium malvæflorum, B. et R. | S | S | — | — | * | — |

| „ pyrenaicum, L. | M | M | * | — | — | — |

| „ molle, L. | S | — | * | — | — | — |

| „ rotundifolium, L. | M | M | * | — | — | — |

| „ lucidum, L. | S |M S| * | — | — | — |

| „ robertianum, L. var. | M | — | * | — | — | — |

|Erodium Jacquinianum, F. et M. |M S| — | | * | — | — |

| „ malacoides, L. | M | — | — | * | | — |

| „ guttatum, W. | M | — | — | — | * | — |

|Oxalis corniculata, L. | M | — | * | — | | — |

|Ruta chalepensis, L. |M S| — | — | * | — | |

|Rhamnus Alaternus, L. | M | M | — | * | — | — |

| „ lycioides, L. | — | M | — | — | * | |

|Acer monspessulanum, L. | M | — | * | — | — | — |

|Pistacia Lentiscus, L. | M | M | — | * | — | — |

|Lotononis maroccana, Ball | M | M | — | — | | * |

|Argyrolobium Linnæanum, Walp. var. |M S| — | — | * | — | |

| „ stipulaceum, Ball | — | M | — | — | — | * |

|Adenocarpus anagyrifolius, Coss. | M | M | — | — | — | * |

|Genista dasycarpa (Coss.) | M | — | — | — | — | * |

| „ myriantha, Ball | | M | — | — | — | * |

| „ florida, L. var. | M | — | — | — | * | — |

|Cytisus Balansæ, Boiss. var. | S | S | — | — | * | — |

| „ albidus, D.C. | — | M | — | — | — | * |

| „ Fontanesii, Spach | M | — | — | — | * | — |

|Ononis atlantica, Ball | — | M | — | — | — | * |

| „ antiquorum, L. | — | M | — | * | — | — |

|Trigonella monspeliaca, L. | M | | — | * | — | — |

| „ polycerata, L. et var. | S | M | — | — | * | — |

|Medicago lupulina, L. | M | — | * | — | — | — |

| „ suffruticosa, Ram. | S | S | — | — | * | — |

| „ turbinata, W. vars. | M | M | — | * | — | — |

| „ denticulata, W. | — | M | * | — | — | — |

| „ minima, Lam. | M | — | * | — | — | — |

|Melilotus indica, All. | M | — | — | * | — | — |

|Trifolium atlanticum, Ball | S | | — | — | — | * |

| „ glomeratum, L. var. | S | — | * | — | — | — |

| „ repens, L. | M | — | * | | — | — |

| „ humile, Ball | S | | | | | * |

| „ tomentosum, L. | M | — | | * | | — |

|Anthyllis Vulneraria, L. et var. |M S| — | * | — | — | — |

| „ tetraphylla, L. | M | — | — | * | — | — |

|Lotus cytisoides, D. C. | M | — | — | * | — | |

|Coronilla pentaphylla, Desf. | M | — | — | — | * | |

| „ ramosissima, Ball | M | — | — | | — | * |

| „ minima, L. | M | — | * | | — | — |

| „ scorpioides, L. | M | — | — | * | — | — |

|Hippocrepis atlantica, Ball | S | — | — | | — | * |

| „ multisiliquosa, L. var. | M | — | — | * | — | — |

|Psoralea bituminosa, L. | M | — | — | * | — | — |

|Colutea arborescens, L. | M | — | * | — | — | — |

|Astragalus sesameus, L. | M | — | — | * | — | — |

| „ Reinii, Ball | S | — | — | — | — | * |

| „ Glaux, L. var. | M | — | — | — | * | — |

| „ atlanticus, Ball | M | — | — | — | — | * |

| „ ochroleucus, Coss. | S | — | — | — | — | * |

| „ incurvus, Desf. | M | — | — | — | * | |

|Vicia onobrychoides, L. | S | — | — | * | — | — |

| „ glauca, Presl. var. | S | — | — | * | — | |

| „ sativa, L. vars. |M S| — | * | — | — | — |

|Lathyrus aphaca, L. | M | — | * | — | — | — |

| „ sphæricus, Retz. | M | | — | * | — | |

|Ceratonia siliqua, L. | M | M | | * | — | — |

|Prunus prostrata (Labill.) | S | S | | * | — | — |

|Poterium sanguisorba, L. | M | | * | — | — | — |

| „ verrucosum, Ehrnb. var. | M | | — | * | — | — |

| „ anceps, Ball | S | S | — | — | — | * |

| „ ancistroides, Desf. | | M | — | — | * | |

|Rosa canina, L. var. | M | M | * | — | — | |

| „ Seraphini, Viv. | S | S | — | * | — | — |

|Saxifraga globulifera, Desf. |M S|M S| | — | * | — |

| „ tridactylites, L. | S | | * | — | — | — |

| „ granulata, L. | S | S | * | — | — | — |

|Ribes Grossularia, L. |M S| S | * | — | — | |

|Cotyledon umbilicus, L. | M | M | * | — | — | — |

|Sedum modestum, Ball | M | M | — | — | — | * |

| „ dasyphyllum, L. var. | M | M | * | — | — | — |

| „ acre, L. |M S|M S| * | — | — | — |

|Sempervivum atlanticum, Ball | M | — | — | — | — | * |

|Monanthes atlantica, Ball | — | S | — | — | — | * |

|Bryonia dioïca, Jacq. | M | — | * | — | | — |

|Eryngium Bourgati, Gouan, var. | — | S | — | — | * | — |

| „ variifolium, Coss. | M | — | — | | — | * |

|Bupleurum spinosum, L. | S | S | — | * | | — |

| „ acutifolium, Coss. | M | M | — | — | * | — |

| „ oblongifolium, Ball | M | — | — | | — | * |

| „ lateriflorum, Coss. | M | — | — | | — | * |

|Deverra scoparia, Coss. et Dur. | — | M | — | — | * | — |

|Carum mauritanicum, B. et R. | M | M | — | — | * | — |

|Pimpinella Tragium, Vill. | M | — | — | * | — | — |

|Tinguarra sicula, L. | — | M | — | * | — | — |

|Scandix pecten Veneris, L. | M | — | * | — | — | — |

|Kundmannia sicula, L. | M | | — | * | — | — |

|Meum atlanticum, Coss. | | S | | — | — | * |

|Heracleum Sphondylium, L. | S | | * | | — | — |

|Bifora testiculata, L. | M | — | — | * | — | — |

|Caucalis latifolia, L. | M | — | * | — | — | — |

| „ daucoides, L. | — | M | * | — | — | — |

| „ leptophylla, L. |M S| M | — | * | — | — |

| „ cœrulescens, Boiss. | M | — | — | — | * | — |

|Elæoselinum meoides, Desf. | M | — | — | * | — | — |

|Hedera Helix, L. | M | — | * | — | — | — |

|Sambucus nigra, L. | M | M | * | — | — | — |

|Viburnum Tinus, L. | — | M | — | * | — | — |

|Lonicera etrusca, Santi | M | | — | * | — | — |

|Putoria calabrica, L. | M | — | — | * | — | — |

|Callipeltis cucullaria, L. | — | M | — | * | — | — |

|Rubia tinctorum, L. | S | — | | * | | — |

| „ peregrina, L. et var. | M | — | * | — | | — |

|Galium Poiretianum, Ball | M | — | — | — | * | — |

| „ corrudæfolium, Vill. | — | S | — | * | — | — |

| „ sylvestre, Poll. var. | S | — | * | — | — | — |

| „ acuminatum, Ball |M S| | — | — | — | * |

| „ noli-tangere, Ball | — | M | — | — | — | * |

| „ tunetanum, Lam. | M | — | — | — | * | — |

| „ parisiense, L. var. |M S|M S| * | — | — | — |

| „ tricorne, With. | S | M | * | — | — | — |

| „ spurium, L. |M S| S | * | — | — | — |

| „ murale, L. | — | M | — | * | — | — |

|Asperula aristata, L. var. | | M | | * | — | — |

| „ hirsuta, Desf. | M | — | — | — | * | — |

|Crucianella angustifolia, L. | M | | | * | — | — |

|Sherardia arvensis, L. | M | — | * | | — | — |

|Centranthus angustifolius, D. C. |M S| — | | * | | — |

| „ calcitrapa, L. | S | S | — | * | | |

|Valerianella discoidea, W. | M | — | — | * | — | — |

| „ auricula, D. C. |M S| M | * | — | — | |

| „ carinata, Loisel. | — | M | * | — | — | |

|Scabiosa stellata, L. | M | — | — | * | — | — |

|Pterocephalus depressus, Coss. |M S| M | — | — | — | * |

|Bellis annua, L. var. | — | M | — | * | — | — |

| „ cœrulescens, Coss. |M S|M S| | — | — | * |

|Evax Heldreichii, Parl. | S | | | * | — | — |

|Micropus bombycinus, Lag. | M | M | — | * | | — |

|Filago germanica, L. var. | — | M | * | | — | |

| „ heterantha, Rafin. | S | S | — | * | — | — |

|Filago gallica, L. | M | M | * | — | — | — |

|Phagnalon saxatile, L. | M | M | — | * | — | — |

| „ atlanticum, Ball | M | — | — | — | — | * |

|Gnaphalium luteo-album, L. | M | M | * | | — | — |

| „ helichrysoides, Ball | S | | — | — | — | * |

|Inula montana, L. | M | | — | * | | |

|Pulicaria mauritanica, Coss. | M | — | — | — | | * |

|Odontospermum aquaticum, L. | M | — | — | * | — | — |

|Anacyclus depressus, Ball | S | — | | — | — | * |

| „ valentinus, L. | — | M | — | * | — | — |

|Achillea ligustica, All. et var. | M | M | — | * | — | |

|Anthemis tuberculata, Boiss. | — | S | — | | * | |

| „ heterophylla (Coss.). | M | M | — | | — | * |

|Chrysanthemum Gayanum (Coss.) et var. |M S|M S| — | — | * | — |

| „ atlanticum, Ball | S | S | — | — | — | * |

| „ Catananche, Ball | S | S | — | — | — | * |

|Senecio lividus, L. var. | S | — | — | * | — | — |

| „ giganteus, Desf. | M | M | — | — | * | — |

|Calendula maroccana, Ball | M | M | — | — | — | * |

|Echinops spinosus, L. | M | — | — | * | — | |

|Xeranthemum modestum, Ball | M | M | — | — | — | * |

|Atractylis cancellata, L. | M | M | — | * | — | — |

| „ macrophylla, Desf. | M | — | — | — | * | — |

|Carduus macrocephalus, Desf. | M | — | — | * | — | — |

| „ Ballii, H. fil. |M S| M | — | — | — | * |

|Cnicus echinatus Desf. | M | — | — | * | — | — |

| „ ornatus, Ball | — | M | — | — | — | * |

| „ chrysacanthus, Ball | M | — | | | — | * |

| „ Casabonæ, L. | S | — | — | * | — | — |

|Stæhelina dubia, L. var. | — | M | | * | — | — |

|Centaurea incana, Desf. var. | M | — | | * | — | — |

| „ Salmantica, L. var. | M | M | | * | — | — |

|Carthamus cœruleus, L. var. |M S| — | — | * | — | — |

|Carduncellus lucens, Ball |M S| — | — | — | — | * |

|Catananche cærulea, L. et var. | M | M | — | * | — | — |

| „ cæspitosa, Desf. | — | S | — | | * | — |

|Tolpis umbellata, Bert. | M | — | — | * | — | |

|Rhagadiolus stellatus, L. | M | M | — | * | | |

|Crepis taraxacifolia, Thuil. var. | M | | * | — | | |

| „ Hookeriana, Ball | — | S | — | — | — | * |

|Phæcasium pulchrum, L. | S | S | * | — | — | — |

|Hieracium Pilosella, L. | S | S | * | | — | |

|Hypochæris glabra, L. var. | M | — | * | — | — | — |

| „ leontodontoides, Ball | S | | — | — | — | * |

|Leontodon autumnalis, L. var. | S | — | * | — | | — |

| „ Rothii, Ball | M | M | | * | | — |

| „ helminthioides, Coss. | — | M | | — | — | * |

|Taraxacum officinale, Wigg. var. | S | S | — | * | — | — |

|Lactuca viminea, L. | M | — | — | — | * | |

| „ tenerrima, Pourr. | M | M | * | — | | |

| „ saligna, L. | M | — | * | — | | |

|Sonchus oleraceus, L. | — | M | — | * | | — |

| „ asper, Vill. | M | — | * | | | — |

|Microrhynchus nudicaulis, L. | M | — | * | — | — | — |

| „ spinosus (Forsk.) | M | — | * | — | — | — |

|Scorzonera undulata, Vahl. | M | — | — | * | — | — |

| „ pygmæa, S. et S. | S | — | — | * | | — |

|Jasione atlantica, Ball | S | — | — | — | * | — |

|Campanula maroccana, Ball | M | — | — | * | — | |

| „ rapunculus, L. | M | — | — | — | — | * |

| „ Lœfflingii, Brot. | M | — | — | — | | * |

|Specularia falcata (Ten.) | — | M | * | — | | — |

|Trachelium angustifolium, Schousb. | M | — | — | | * | — |

|Arbutus Unedo, L. | M | | | * | | — |

|Armeria plantaginea (All.)? | | S | — | — | — | * |

|Asterolinum linum-stellatum, L. | — | M | * | — | — | — |

|Anagallis linifolia, L. et var. |M S| — | * | — | — | — |

|Jasminium fruticans, L. | M | — | — | * | — | — |

|Fraxinus oxyphylla, M. B. | M | M | — | * | — | — |

| „ dimorpha, Coss. et Dur. | M | — | — | * | | — |

|Phillyrea media, L. | M | M | — | * | | — |

|Olea europæa, L. | M | M | — | | * | — |

|Nerium Oleander, L. | M | M | — | * | — | — |

|Convolvulus Cantabrica, L. | M | M | | * | — | — |

| „ undulatus, Cav. | M | — | — | * | — | — |

| „ sabatius, Viv. var. |M S| — | — | * | — | — |

| „ siculus, L. | — | M | — | * | — | — |

| „ althæoides, L. | M | — | | * | — | — |

|Hyoscyamus albus, L. | M | — | — | * | — | — |

|Anchusa atlantica, Ball | M | — | — | * | — | — |

|Lithospermum arvense, L. | S | — | | * | — | — |

| „ incrassatum, Guss. var. | S |M S| | — | — | * |

| „ apulum, Vahl. | M | | * | | — | — |

|Myosotis sylvatica, Hoffm. var. | S | S | — | * | — | — |

| „ hispida, Schlecht. var. | S | — | — | * | — | — |

| „ stricta, Link | S | S | * | — | — | — |

|Cynoglossum Dioscoridis, Vill. et var. |M S| — | * | — | — | — |

|Rochelia stellulata | M | M | * | — | — | — |

|Verbascum calycinum, Ball | M | — | | * | — | — |

|Celsia maroccana, Ball | M | | — | — | — | * |

|Linaria ventricosa, Coss. | M | M | | — | — | * |

|Linaria heterophylla, Desf. | M | M | — | * | — | — |

| „ galioides, Ball et var. | S | — | — | — | — | * |

| „ arvensis, L. var. | S |M S| — | * | — | — |

| „ marginata, Desf. | S | — | — | — | * | — |

| „ lurida, Ball | S | | — | — | | * |

| „ Munbyana, Boiss. et Reut. | M | — | — | — | * | — |

| „ Tournefortii (Poir.) | S | S | — | — | * | — |

| „ rubrifolia, Rob. et Cast. | M | — | — | * | — | — |

|Anarrhinum pedatum, Desf. | M | — | — | — | * | — |

| „ fruticosum, Desf. | — | M | | * | — | — |

|Scrophularia canina, L. var.? | — | M | * | — | — | — |

|Digitalis lutea, L. var. | M | — | * | — | — | |

|Veronica Beccabunga, L. | S | — | * | — | — | — |

| „ cuneifolia, Don. var. | S | S | — | * | — | — |

| „ arvensis L. et var. | S | S | * | — | — | — |

| „ triphyllos, L. | — | M | * | | — | — |

| „ agrestis, L. | S | — | * | — | — | |

| „ hederifolia, L. et var. |M S|M S| * | — | — | |

|Phelipæa cærulea, Vill. | M | | * | — | — | — |

|Orobanche Hookeriana, Ball | M | — | — | — | — | * |

| „ barbata, Poir. | M | — | — | — | * | — |

|Lavandula dentata, L. et var. | M | M | — | * | — | — |

| „ tenuisecta, Coss. |M S|M S| — | — | — | * |

|Mentha rotundifolia, L. | S | — | * | — | — | — |

|Thymus saturejoides, Coss. et var. | M | M | — | — | — | * |

|Thymus Serpyllum, L. var. | S | — | * | — | | — |

| „ lanceolatus, Desf. var. | M | M | — | * | — | — |

| „ maroccanus, Ball | M | — | — | — | — | * |

|Micromeria microphylla, Benth | M | — | — | * | — | |

|Calamintha graveolens, M. B. | M | — | — | * | — | — |

| „ alpina, L. var. | S | S | * | — | — | — |

| „ atlantica, Ball |M S|M S| — | | * | — |

|Hyssopus officinalis, L. | S | S | * | — | — | — |

|Salvia Maurorum, Ball | — | M | — | — | — | * |

| „ clandestina, L. var. |M S| — | * | — | — | |

|Nepeta multibracteata, Desf. | M | — | | — | * | — |

| „ atlantica, Ball | — | M | — | | — | * |

|Sideritis villosa, Coss. |M S|M S| — | — | | * |

| „ scordioides, L. var. | | S | * | — | — | — |

|Lamium amplexicaule, L. |M S|M S| * | — | — | — |

| „ album, L. var. | M | — | * | | — | — |

|Teucrium granatense, B. et R. var. | — | M | — | — | * | — |

| „ polium, L. vars. | M | M | — | * | — | — |

|Ajuga Iva, L. |M S|M S| — | * | — | |

|Globularia Alypum, L. | — | M | — | * | — | — |

|Plantago albicans, L. var. | — | M | — | * | — | — |

|Plantago coronopus, L. var. |M S| M | * | — | — | — |

| „ mauritanica, B. et R. | — | M | — | — | * | |

|Paronychia argentea, Lam. |M S|M S| — | * | — | — |

| „ capitata, Lam. var. |M S| | * | | | — |

| „ macrosepala, Boiss. et var. | M | | — | * | — | — |

|Scleranthus annuus, L. var. | | S | * | | | — |

|Polycnemum Fontanesii, Dur. et Moq. | M | — | — | — | * | |

|Rumex scutatus, L. var. |M S| — | * | — | — | |

| „ Papilio, Coss. | M | — | — | — | — | * |

|Polygonum aviculare, L. | | | * | — | — | — |

|Daphne Gnidium, L. | M | M | — | * | — | — |

| „ Laureola, L. | M | — | * | — | — | — |

|Thymelæa virgata, Endl. var. | M | M | — | — | * | — |

|Osyris alba, L. | — | M | — | * | — | — |

|Aristolochia Pistolochia, L. | M | — | — | * | — | — |

|Euphorbia rimarum, Coss. | M | M | — | — | — | * |

|Quercus Ilex, L. et var. | M |M S| — | * | — | — |

|Salix purpurea, L. var. | M | — | * | — | — | — |

|Populus alba, L. var. | M | M | * | — | — | — |

| „ nigra, L. | M | — | * | — | — | — |

|Ephedra altissima, Desf. | M | — | — | * | — | — |

| „ procera, F. et M. | M | | — | * | — | — |

|Pinus halepensis, Mill. | — | M | — | * | — | — |

|Callitris quadrivalvis, Vent. | M | M | — | — | * | — |

|Juniperus oxycedrus, L. | M | M | | * | | — |

| „ phœnicea, L. et var. | M | | | * | — | — |

| „ thurifera, L. | S | | | | * | — |

|Orchis pyramidalis, L. | M | — | * | — | — | — |

| „ latifolia, L. | S | — | * | — | — | — |

|Ophrys apifera, Huds. | M | — | * | — | — | — |

|Iris germanica, L. | M | — | — | * | — | — |

|Chamærops humilis, L. | M | M | — | * | — | — |

|Gagea foliosa, Schult. | — | S | — | * | — | — |

|Muscari comosum, L. | M | M | — | * | — | — |

|Scilla hispanica, Mill. | | S | — | — | * | — |

|Ornithogalum comosum, L. | S | | * | — | — | — |

| „ tenuifolium Guss. | | S | | * | — | — |

| „ orthophyllum, Ten. | | M | | * | — | — |

| „ pyrenaicum, L. var. | — | M | * | — | — | — |

|Allium paniculatum, L. var. | — | M | | * | — | — |

|Asphodelus microcarpus, Viv. | M | | — | * | — | — |

|Anthericum Liliago, L. var. | M | | * | — | — | |

|Colchicum Civonæ, Guss. | — | S | — | * | — | |

| „ arenarium W. K. var. ? | S | | — |*? | — | — |

|Smilax mauritanica, Desf. | M | — | — | * | | — |

|Asparagus acutifolius, L. | M | — | — | * | — | |

| „ scoparius, Lowe? | M | — | | — | — | * |

|Juncus bufonius, L. | M | M | * | — | — | — |

|Scirpus Savii, S. et M. | M | — | * | — | — | — |

|Carex Halleriana, Asso. | — | M | * | — | — | — |

| „ ambigua, Link. | M | — | — | — | * | — |

| „ fissirostris, Ball | S |M S| — | — | — | * |

|Phalaris nodosa, L. | M | — | — | * | — | — |

|Piptatherum cœrulescens, Desf. |M S| M | — | * | — | — |

|Stipa parviflora, Desf. | M | — | — | * | — | — |

| „ gigantea, Lag.? | M | — | — | * | — | |

| „ nitens, Ball | S | — | — | — | — | * |

|Agrostis verticillata, Vill. | M | — | — | * | — | |

|Phragmites communis, Trin. | M | — | * | — | — | |

|Echinaria capitata, Desf. |M S|M S| | * | | — |

|Aira caryophyllea, L. | |M S| * | — | — | — |

|Trisetum flavescens, L. | M | | * | — | — | — |

|Avena bromoides, Gouan. var. | M | | — | * | — | — |

|Arrhenatherum elatius. L. | — | M | * | — | — | — |

|Poa annua, L. |M S| M | * | — | — | — |

| „ bulbosa, L. |M S|M S| * | — | — | — |

| „ pratensis, L. |M S|M S| * | | — | — |

| „ trivialis, L. |M S| — | * | — | — | — |

|Melica ciliata, L. var. | M | — | * | — | | — |

| „ Cupani, Guss. var. |M S| M | — | * | — | — |

|Dactylis glomerata, L. vars. |M S|M S| * | — | — | — |

|Cynosurus elegans, Desf. | |M S| — | * | — | |

|Festuca rigida, L. | M | — | * | — | — | — |

| „ unilateralis, Schrad. var. | M | — | — | * | — | |

| „ geniculata, L., et var. | M | M | — | * | — | |

| „ duriuscula, var. | S | S | * | — | — | — |

| „ arundinacea, Schreb. | M | M | * | — | — | — |

|Brachypodium pinnatum, L. var. | M | — | * | — | — | — |

| „ distachyum, L. | M | M | — | * | — | — |

|Bromus tectorum, L. |M S| — | * | — | — | — |

| „ madritensis, L. | M | M | * | — | — | — |

| „ mollis, L. vars. |M S| M | * | | — | — |

| „ macrostachys, Desf. var. | M | — | — | * | | — |

|Lolium perenne, L. | M | — | * | — | — | — |

|Triticum hordeaceum, Coss. et Dur. | M | | — | — | * | — |

|Secale montanum, Guss. | M | | — | * | — | |

|Elymus Caput-medusæ, L. var. | M | — | | * | — | |

|Hordeum murinum, L. | M | M | * | — | — | |

|Ægilops ovata, L. | M | M | — | * | — | — |

| „ ventricosa, Tausch. | M | — | — | * | — | — |

|Andropogon hirtus, L. var. | M | — | — | * | | — |

|Cistopteris fragilis, Bernh. | S | S | * | | | — |

|Cheilanthes fragrans, L. | M | — | — | * | | |

|Pteris aquilina, L. | S | | * | | | — |

|Asplenium trichomanes, L. |M S| — | * | | | — |

| „ viride, L. | S | | * | | | |

| „ Adiantum-nigrum, L. | S | | * | | | |

|Notochlæna vellea, Desv. | M | — | — | * | | |

|Ceterach officinarum, Willd. |M S|M S| * | — | | |

|Equisetum ramosissimum, Desf. | M | — | * | — | — | |

|Selaginella, rupestris, (Spreng.) | M | — | — | * | — | |

+----------------------------------------+---+---+---+---+---+---+

|Total number of species 465 |388|225|161|168| 61| 75|

+----------------------------------------+---+---+---+---+---+---+

Before discussing the inferences to be derived from this list, it may

be well to notice some sources of error that, to a slight extent,

affect the results. Although the season of our visit—the second

half of May—was probably the best as regards the middle zone, it

was too early to find the vegetation fully developed in the superior

zone, especially on the highest ridges. It is probable that on this

account the proportion of _Umbelliferæ_ and _Gramineæ_ found in

the higher region is smaller than it would have been at a later

season. At first sight it would appear that the shorter time that

we were able to devote to an examination of the upper region, and

the snow-storm which we encountered in the ascent to the Tagherot

Pass, make the proportion of species found there, as shown by our

lists, unduly small. There can be no doubt that we must have lost

several species owing to these causes, but not enough to vitiate

the results to a serious extent. In confirmation of this opinion it

may be mentioned that although a native employed by M. Cosson has

since made a large collection in the same part of the Great Atlas,

and two German naturalists—MM. Rein and Fritsch—have visited

the head of the Aït Mesan valley, very few species have been added

to the Flora of the higher mountain region.

The first conclusion that strikes a botanist on examining the

foregoing list is that the general type of the vegetation clearly

marks this as belonging to the great Mediterranean Flora, which

extends, with local peculiarities, from Persia and Belutschistan to

the Atlantic Islands. Out of 248 genera represented in the Flora of

these valleys there is not one which is not common to other portions

of the Mediterranean region, and one only (_Monanthes_) is confined

to the Great Atlas and the Canary and Cape de Verde Islands, all the

others being types more or less widely spread. Further than this,

the proportion borne by each of the prevailing natural orders to

the whole vegetable population is pretty nearly the same that we

are accustomed to find in the mountain regions of the Mediterranean

region.

The materials for a comparison are unfortunately yet incomplete

as regards many of the mountain districts which are best fitted

for the purpose. The Flora of the Lesser Atlas of Algeria, as well

as that of the rest of the French possessions in Africa, will be

fully known only on the appearance of the important work promised

by M. Cosson. The Flora of Spain by MM. Willkomm and Lange is yet

unfinished, and there is the further difficulty that those authors

have admitted a large number of plants to the rank of species

which many botanists reckon only as varieties. M. Boissier’s

great work, the ‘Flora Orientalis,’ is also unfinished, and no

adequate materials exist for compiling lists of the plants of the

Greek mountains, of those of Asia Minor, or of the Lebanon chain,

all of which would afford interesting materials for comparison. In

the following table I have taken for comparison the Flora of

the Sierra Nevada, with the neighbouring mountains of the ancient

kingdom of Granada above the level of about 800 metres, compiled from

Boissier’s ‘Voyage botanique dans le Midi de l’Espagne;’ that

of the Bulgardagh (the principal group of the Cilician Taurus), from

a list published by M. Pierre de Tchihatcheff in the ‘Bulletin of

the French Botanical Society;’ that of Dalmatia, from Visiani’s

excellent ‘Flora Dalmatica;’ and that of the southern slopes

of the chain of the Alps from Nice to the Karst, formed by myself

from all available sources.

In the same table I have introduced, for the purpose of further

comparison, separate columns for the middle and superior regions

of the Great Atlas valleys, and in connection with the last I have

added in a separate column the results for the higher zone of the

Sierra Nevada. Under each heading I have stated

TABLE. I—_Showing the number of species of each of the principal

groups and natural orders of plants in two valleys of the Great Atlas

compared with other mountain districts in the Mediterranean region._

+---------------+-----------+-----------+-----------+-----------+

| | 455 sp. | 341 sp. | 176 sp. | 800 m. |

| | | | | 890 sp. |

+---------------+-----------+-----------+-----------+-----------+

|Dicotyledones | 391 86·0| 286 83·9| 154 87·5| 762 85·6|

| | | | | |

|Monocotyledones| 64 14·0| 55 16·1| 22 12·5| 128 14·4|

| | | | | |

|Compositæ | 63 13·8| 46 13·5| 22 12·5| 119 13·4|

| | | | | |

|Leguminosæ | 48 10·5| 38 11·1| 14 8·0| 67 7·5|

| | | | | |

|Gramineæ | 39 8·6| 37 10·8| 14 8·0| 59 6·6|

| | | | | |

|Caryophylleæ | 26 5·7| 14 4·1| 15 8·5| 40 4·5|

| | | | | |

|Cruciferæ | 25 5·5| 7 2·1| 21 11·9| 49 5·5|

| | | | | |

|Labiatæ | 23 5·0| 18 5·3| 11 6·3| 54 6·1|

| | | | | |

|Scrophularineæ | 21 4·6| 13 3·8| 10 5·7| 37 4·2|

| | | | | |

|Umbelliferæ | 20 4·4| 16 4·7| 5 2·8| 50 5·6|

| | | | | |

|Rubiaceaæ | 18 4·0| 15 4·4| 7 4·0| 20 2·2|

| | | | | |

|Papaveraceæ | 10 2·2| 8 2·3| 3 1·7| 10 1·1|

| | | | | |

|Geraniaceaæ | 10 2·2| 8 2·3| 4 2·3| 10 1·1|

| | | | | |

|Liliaceæ | 10 2·2| 6 1·8| 4 2·3| 15 1·7|

| | | | | |

|Boragineæ | 9 2·0| 5 1·5| 6 3·4| 18 2·0|

| | | | | |

|Ranunculaceæ | 8 1·8| 5 1·5| 4 2·3| 28 3·1|

| | | | | |

|Cistineæ | 7 1·5| 6 1·8| 1 0·6| 23 2·6|

| | | | | |

|Rosaceæ | 7 1·5| 4 1·2| 3 1·7| 26 2·6|

| | | | | |

|Campanulaceæ | 6 1·3| 5 1·5| 1 0·6| 9 1·0|

| | | | | |

|Convolvulaceæ | 5 1·1| 5 1·5| 1 0·6| 3 0·3|

| | | | | |

|Coniferæ | 5 1·1| 4 1·2| 1 0·6| 10 1·1|

| | | | | |

|Saxifrageæ | 4 0·9| 4 1·2| 4 2·3| 12 1·3|

| | | | | |

|Cyperaceæ | 4 0·9| 4 1·2| 1 0·6| 17 1·9|

| | | | | |

|Gentianeæ | | | | 7 0·8|

| | | | | |

|Primulaceæ | 2 0·4| 2 0·6| 1 0·6| 7 0·8|

| | | | | |

|Junceæ | 1 0·2| 1 0·3| | 11 1·2|

+---------------+-----------+-----------+-----------+-----------+

[**Continued]

+---------------+-----------+-----------+-----------+-----------+

| | Sierra | 882 sp. | 2,002 sp. | the Alps. |

| | Nevada. | | | 2,545 sp. |

| | 486 sp. | | | |

+---------------+-----------+-----------+-----------+-----------+

|Dicotyledones | 419 86·2| 808 91·6| 1594 79·6| 2035 80·0|

| | | | | |

|Monocotyledones| 67 13·8| 74 8·4| 408 20·4| 510 20·0|

| | | | | |

|Compositæ | 63 13·0| 97 11·0| 235 11·7| 343 13·5|

| | | | | |

|Leguminosæ | 32 6·6| 93 10·5| 222 11·1| 172 6·8|

| | | | | |

|Gramineæ | 37 7·6| 38 4·3| 173 8·6| 176 6·9|

| | | | | |

|Caryophylleæ | 29 6·0| 81 9·2| 74 3·7| 121 4·8|

| | | | | |

|Cruciferæ | 37 7·6| 84 9·5| 98 4·9| 139 5·5|

| | | | | |

|Labiatæ | 28 5·8| 67 7·0| 100 5·0| 89 3·5|

| | | | | |

|Scrophularineæ | 28 5·8| 39 4·4| 66 3·3| 109 4·3|

| | | | | |

|Umbelliferæ | 23 4·7| 33 3·7| 113 5·6| 113 4·4|

| | | | | |

|Rubiaceaæ | 12 2·5| 19 2·2| 26 1·3| 34 1·3|

| | | | | |

|Papaveraceæ | 6 1·2| 12 1·4| 14 0·7| 14 0·6|

| | | | | |

|Geraniaceaæ | 6 1·2| 6 0·7| 17 0·8| 23 0·9|

| | | | | |

|Liliaceæ | 9 1·9| 23 2·6| 61 3·0| 52 2·0|

| | | | | |

|Boragineæ | 11 2·3| 23 2·6| 40 2·0| 39 1·5|

| | | | | |

|Ranunculaceæ | 15 3·1| 11 1·2| 53 2·6| 87 3·4|

| | | | | |

|Cistineæ | 10 2·1| 1 0·1| 11 0·5| 10 0·4|

| | | | | |

|Rosaceæ | 20 4·1| 21 2·4| 57 2·8| 93 3·7|

| | | | | |

|Campanulaceæ | 6 1·2| 21 2·4| 26 1·3| 46 1·8|

| | | | | |

|Convolvulaceæ | 2 0·1| 4 0·5| 10 0·5| 9 0·4|

| | | | | |

|Coniferæ | 8 1·6| 15 1·7| 15 0·7| 11 0·4|

| | | | | |

|Saxifrageæ | 9 1·9| 2 0·2| 9 0·4| 52 2·0|

| | | | | |

|Cyperaceæ | 12 2·5| 7 0·8| 43 2·2| 119 4·7|

| | | | | |

|Gentianeæ | 5 1·0| 4 0·5| 14 0·07| 31 1·2|

| | | | | |

|Primulaceæ | 6 1·2| 8 0·9| 12 0·6| 60 2·4|

| | | | | |

|Junceæ | 9 1·9| | 8 0·4| 31 1·2|

+---------------+-----------+-----------+-----------+-----------+

the whole number of phanerogamous species included in the Flora

of the region, and opposite the name of each natural order I

have entered the number of species found in each region, and

the percentage proportion which this number bears to the entire

flora. Besides the orders which bear the largest proportion in the

Great Atlas Flora I have enumerated those that usually characterise

the vegetation of high mountains in this part of the world, though

several of these are little, or not at all, represented in the

Flora of the Great Atlas.

Confining the comparison in the first instance to the figures given

for the Atlas Flora as a whole in the first column, and those given

in the fourth, sixth, seventh, and eighth columns respectively,

for the Sierra Nevada, the Bulgardagh, Dalmatia, and the southern

side of the Alps, we remark in the first place that _Monocotyledons_

bear about the same proportion to _Dicotyledons_ in the Great Atlas

that they do in the Sierra Nevada, the percentage here being much

larger than it is in the Bulgardagh, and considerably less than

in Dalmatia or the Southern Alps. In this part of the world this

percentage in the Flora of a given region mainly depends upon the

number of _Gramineæ_ and _Cyperaceæ_. The abundance of the latter

group in the Alps doubtless arises from the fact that at a former

period physical conditions favoured the migration of a large number

of northern species that have been unable to extend to the more

southern mountain regions of the Mediterranean area.

In all the regions under consideration we find, with a single

exception, that the same eight natural orders take precedence of

all others as regards the number of species that they exhibit, the

aggregate in every case exceeding one-half of the whole phanerogamous

Flora. These natural orders are _Compositæ_, _Leguminosæ_,

_Gramineæ_, _Caryophylleæ_, _Cruciferæ_, _Labiatæ_,

_Scrophularineæ_, and _Umbelliferæ_. The exception arises from

the prevalence, already noticed, of _Cyperaceceæ_ in the Flora

of the Southern Alps. In comparing the figures in the Great Atlas

column with those for the other areas above enumerated, it is well

to recollect that our materials are taken from a district much more

limited in extent than the others, and are necessarily imperfect,

because obtained from a single short visit to each valley at a season

when many species are yet undeveloped. It is probable, for instance,

that the proportion of _Umbelliferæ_ would be increased if the

whole Flora were better known. Subject to this remark, it will

be seen, as might be expected, that the constituents of the Great

Atlas Flora show more analogy with those of the Sierra Nevada and

Bulgardagh Floras than with those of Dalmatia and the Southern Alps;

but the proportion of _Compositæ_ is larger than in any of them

(nearly 14 per cent). In comparing the vegetation of a small district

with that of a large one it must be recollected that a small natural

group containing a few widely spread species, such as _Geraniaceæ_,

is likely to show a larger percentage proportion to the whole Flora

in the small district than in the larger one. It may happen that

the same species are spread through both regions; but in one case

the number is to be compared with a small total, in the other with a

much larger one. This remark has a bearing on the fact that in the

Great Atlas Flora the natural orders that bear an unusually large

proportion to the total number of the Flora are _Leguminosæ_,

_Caryophylleæ_, _Rubiaceceæ_, _Papaveraceæ_, _Geraniaceæ_,

and _Convolvulaceæ_. On the other hand, there is a remarkable

deficiency in the natural orders that especially characterise

the Flora of the Alps, and in a less degree, the high mountains

of Southern Europe. These are _Ranunculaceceæ_, _Rosaceæ_,

_Saxifrageæ_, _Primulaceæ_, _Junceæ_, and _Cyperaceæ_; not to

speak of _Gentianeæ_, which are here altogether absent.

If, instead of regarding the Atlas Flora as a whole, we examine

separately the figures given in the several columns for the

middle and superior zones respectively, we find very different

proportions for the chief natural orders, except for _Compositæ_

and _Leguminosæ_ which are in both very numerous. In the middle

region of the Atlas these two orders represent very nearly

one-fourth of the phænogamous Flora. After these _Gramineæ_,

_Rubiaceæ_, _Papaveraceæ_, _Geraniaceæ_, _Cistineæ_, and

_Convolvulaceæ_ are, in the middle region, unusually frequent,

while _Cruciferæ_, _Rosaceæ_, _Boragineæ_, and _Liliaceæ_

are remarkably deficient. In the superior zone, on the other hand,

the proportion of _Compositæ_ and _Leguminosæ_ is less excessive,

making jointly a little over one-fifth of the whole Flora of the

upper region. The most marked characteristic here is the very

large proportion of _Cruciferæ_, being less by one species only

than the number of _Compositæ_. Taking into account the number of

individuals as well as that of species, this must be regarded as

the dominant element in the Flora of the higher region of the Great

Atlas, affording as it does 12 per cent of the whole Flora. The only

region in which this characteristic is approached is the Bulgardagh

in Cilicia, where _Cruciferæ_ supply near one-tenth of the whole

list. _Caryophylleæ_ also form an unusually large element in the

Flora of the upper zone of the Atlas; but, unlike _Cruciferæ_,

this order exhibits no endemic species, and four-fifths of the whole

number are common plants of Central and Northern Europe. _Rubiaceæ_

and _Boragineæ_ have more representative species than is usual in

mountain Floras; while there are but three species of _Rosaceæ_

in our list; and _Campanulaceæ_, _Primulaceæ_, _Coniferæ_,

and _Cyperaceæ_ are each represented by a single species, and

_Gentianeæ_ and _Junceæ_ are altogether absent from the higher

zone.

Although statistical results, such as those given above, are not

without interest, as throwing light upon the general characteristics

of the Flora of a given region, any rational grounds for speculation

as to the real affinities and past history of the vegetation must

be derived from a closer examination of the individual species

of which it is constituted. It is at least conceivable that two

Floras should exhibit similar proportions of species belonging to

the several natural groups, with no identical species, and with

little or no indication of community of origin. The particulars

given in our general list will have already led the reader to infer

that the results of an examination into the distribution of the

individual species that go to make up the Great Atlas exhibit some

very peculiar features. Taking the totals at the foot of our list,

and excluding cryptogams, it is seen that more than one-third of

the species are plants of Middle and Northern Europe, while about

one-sixth is made up of endemic species peculiar to Marocco, and,

with few exceptions, not known out of the Great Atlas, more than half

of the whole list belonging to one or other of these categories. The

results, as shown in the following table, are still more remarkable

when we separately examine the zones into which mountain vegetation

is naturally divided. As in the former table the figures first

entered in each column represent the number of species belonging to

each category, those next given showing the percentage proportion

borne by that number to the total proportion of each region.

TABLE II.—_Showing the distribution of the species of flowering

plants included in the Flora of the Great Atlas, and of the Sierra

Nevada of Granada,[2] and the Bulgardagh in Cilicia.[3]_

+-------------+------------+-------------+------------+------------+

+-------------+------------+-------------+------------+------------+

|Great Atlas, | 154 33·8| 165 36·2| 61 13·4| 75 16·6|

|1,200 m. | | | | |

|455 sp. | | | | |

| | | | | |

|Middle Zone | 106 31·1| 141 41·3| 46 13·5| 48 14·1|

|m. to 2,000 | | | | |

|m. 341 sp. | | | | |

| | | | | |

|Superior Zone| 78 44·3| 43 24·4| 20 11·4| 35 19·9|

|to 3,500 m. | | | | |

|176 sp. | | | | |

| | | | | |

|Superior Zone| 209 43·0| 74 15·2| 104 21·4| 99 20·4|

|1,600 m. | | | | |

|486 sp. | | | | |

| | | | | |

|Bulgardagh | 159 18·0| 359 40·7| 157 17·8| 207 23·5|

|882 sp. | | | | |

+-------------+------------+-------------+------------+------------+

From this table we see that while over one-third of the whole

Atlas Flora consists of plants of Central and Northern Europe,

the proportion reaches nearly to one-half in the higher region

(above 2,000 metres); and also that the proportion of endemic

species, which in the aggregate is one-sixth of the whole, rises

to one-fifth in the upper zone. On the other hand, the proportion

of purely Mediterranean species, which amounts to 55 per cent. in

the Flora of the middle zone, falls below 36 per cent. in the upper

region. Of these Mediterranean species the large majority (more

than two-thirds) are widely distributed plants, several of them

extending to the mountains of Asia Minor, and twenty species only

are exclusively confined to the Great Atlas and to the mountains of

Southern Spain, the Lesser Atlas, or the Pyrenees. There is nothing

in the distribution of these latter plants to indicate any special

connection between the Atlas and any one of the mountain regions

above mentioned. Six Atlas species are common to Southern Spain

and the Algerian Atlas, six more are known only on the mountains of

Southern Spain, five have been hitherto supposed to be peculiar to

the Lesser Atlas, and three are elsewhere confined to the Pyrenees.

Some further light may be thrown on the origin of the Great Atlas

Flora by considering the affinities of the plants which are reckoned

in our list as endemic in Marocco, nearly all being confined, so far

as we know, to the chain of the Great Atlas. Although all of these,

along with some that we have classed as mere varieties, would be

counted as distinct species by many botanists, a considerable number,

amounting to more than a quarter of the whole, are, according

to the views expressed elsewhere by the writer,[4] to be ranked

as sub-species. But here again we fail to discover indications

of special relations between the Great Atlas Flora and that of

neighbouring mountain regions. Ranking as sub-species twenty-one

out of the seventy-five endemic forms enumerated in our list, we

find that ten of these are allied to widely spread Mediterranean

species, three are related to plants of Central Europe, three to

species common to Algeria and Southern Spain, three more to species

confined to the Spanish peninsula, and two to endemic Algerian forms.

If we scrutinise in the same manner the endemic forms of the higher

region of the Great Atlas, we find that out of the thirty-five

enumerated eight, or less than one-fourth, are to be ranked as

sub-species. Of these, three are nearly allied to wide-spread

Mediterranean species, one to a plant common to Spain and Algeria,

two to endemic Spanish species, one to an Algerian endemic form,

and one is related to a species indigenous in the Alps and other

high mountains of Central Europe.

While recognising the fact that the relations between the vegetable

population of the Great Atlas and that of the south of Spain are

less close than might have been expected on theoretical grounds,

we must yet admit that, on the whole, the Great Atlas is more

nearly connected in a botanical sense with this than with any other

mountain region that is known to us; and it becomes a matter of

some interest to compare closely the list of species obtained by us

in the Atlas, with the comparatively well known Flora of Southern

Spain. The results of this comparison are given for the Great Atlas

generally, and for the superior zone separately, in the following

table, in which the Atlas species are distinguished under five

heads: 1, those found in the higher region of the Sierra Nevada;

2, in the mountain region of Andalusia; 3, in the lower warm region

below the level of about 2,000 feet; 4, absent from Southern Spain,

but found in the central or northern provinces; and 5, those not

included in the Spanish Flora.

TABLE III.

[A: Superior region, Sierra Nevada

B: Mountain region of Andalusia

C: Lower region of Southern Spain

D: Central, or Northern Spain, exclusively

E: Absent from Spain]

+-------------------------------------------+----+----+----+----+----+

| | A | B | C | D | E |

+-------------------------------------------+----+----+----+----+----+

|Great Atlas Valleys. 455 sp. | 103| 82| 100| 44| 126|

|Superior region of the Great Atlas. 176 sp.| 61| 19| 20| 21| 55|

|Great Atlas Valleys. 455 sp. | 103| 82| 100| 44| 126|

|Superior region of the Great Atlas. 176 sp.| 61| 19| 20| 21| 55|

+-------------------------------------------+----+----+----+----+----+

The figures given in this table are of much interest, proving,

as they do, the wide differences that exist between the Floras

of two mountain regions not widely separated from each other, and

exposed to climatal conditions not altogether dissimilar. We see

that three-sevenths of the plants found in the higher region of the

Great Atlas are absent from the South of Spain, and that the same

remark applies to considerably more than one-third of all the plants

found in the portion of the Great Atlas visited by us, although a

notable proportion (in both cases) is to be found in Central and

Northern Spain. Especially noteworthy is the fact that many of the

species thus absent in Southern Spain are plants of Central Europe,

most of which extend to the northern part of the Spanish Peninsula,

although some of them are altogether wanting in the Floras of Spain

and Portugal.

A simple inspection of our list suffices to show that it discloses

no trace of affinity between the Great Atlas Flora and that of the

Canary Islands, or, to use a term of wider geographical import, that

of Macaronesia. The few species belonging exclusively to the latter

region and to Marocco are nearly all confined to the coast region.[5]

Almost all the species common to the Atlas and to Macaronesia are

widely spread Mediterranean plants that ascend from the low country

into the valleys. The solitary mountain plant belonging to this

category is _Arabis albida_, the southern form of _A. alpina_,

common in the East, and in the Apennines of Central and Southern

Italy, but which, strange to say, has not been found in Spain. In

Teneriffe, as in the Atlas, it ascends to about the level of 2,700

metres above the sea. The only fact suggesting a remote affinity

between the Great Atlas and Macaronesian Floras is the presence in

the former of a species of _Monanthes_, a generic group hitherto

found only in the Canary and Cape de Verde Islands. But the absence

of any closer connection clearly shows that the separation between

the Macaronesian group and the main land of Africa must date from

a period, even geologically speaking, remote.

When we come to sum up the results of the foregoing discussion,

bearing always in mind the fact that we possess a mere fragment of

the Flora of the Great Atlas, and that future exploration may largely

modify our conclusions, we find as its most striking characteristic

the presence of a large proportion of plants of Central and Northern

Europe, along with a considerable number of peculiar species not

hitherto known elsewhere; and we observe that these two constituents,

which together form about one-half of the Flora of the region here

discussed, amount to very nearly two-thirds of the species found

in the higher zone. We remark that of these northern plants none

are of Alpine or Arctic type, that nearly all belong to what has

been called the Germanic Flora, and all are plants of the plain,

not in Europe characteristic of mountain vegetation.[6]

Of the species belonging to the Mediterranean region, which

constitute more than one-half of the vegetation of the middle zone,

and about one-third of that of the higher zone of the Atlas, the

large majority are widely diffused species. The remaining number,

for the most part mountain plants, may be divided into three nearly

equal sections, some being common both to Southern Spain and Algeria,

others to the Atlas and Southern Spain exclusively, and others to

the Great Atlas and the Lesser Atlas of Algeria. Nothing indicates

any special connection with the Floras of either of those regions.

The absence of any distinct generic types from the Great Atlas

Flora has already been remarked. It is not less important to note

the absence of any of the southern types, characteristic of the

sub-tropical zone, some representatives of which are found in the

same or even in higher latitudes, in Arabia, Syria, Persia, and

Northern India, and which also appear in the Canary Islands. We

finally are led to regard the mountain Flora of Marocco as a

southern extension of the European temperate Flora, with little or

no admixture of extraneous elements, but so long isolated from the

neighbouring regions, that a considerable number of new specific

types have here been developed. The physical causes which have

operated to bring about these conditions are doubtless numerous and

complicated, but the most important of them are easily indicated. The

influence of the Atlantic climate, and the prevailing direction

of the aërial and oceanic currents, have fitted this region for

the habitation of such northern species as do not require a long

period of winter repose. In the present condition of the African

continent, the Great Desert, extending for a distance of 700 or 800

miles between the Atlas and the river region of tropical Africa,

effectually prevents the northward extension of most forms of animal

and vegetable life; while in a period geologically recent, it is

most probable that the same area was occupied by a wide gulf, which

served the same purpose of barring the migration of southern forms.

It may be premature to attempt to trace in further detail the

origin of the Great Atlas Flora; but the facts already ascertained

certainly authorise some negative inferences. The absence of plants

of Arctic type proves that if some mountains of Southern Europe

received contributions to their vegetation during the glacial

period by means of floating ice-rafts, that mode of diffusion did

not extend to the Great Atlas. If we suppose that during the glacial

period the temperature of the region north of the Atlas had fallen

so low as to permit the migration of northern species across the

intervening low country, we find it difficult to understand why so

many species which, according to this theory, must have retreated

to the Atlas on the subsequent rise of temperature, should have

failed also to find a refuge in the mountains of Southern Spain.

It is a further difficulty that if the constituents of the Great

Atlas Flora had, to a large extent, travelled by the route here

indicated, other species, now inhabiting the mountains of Southern

Spain, could scarcely fail to take the same road, and a much nearer

connection than is now apparent would have been established between

the Floras of these two mountain regions.

It is, at least, possible that the wide diffusion of many of the

species constituting the so-called Germanic Flora may date from

a period much more remote than is ordinarily supposed; and it is

a circumstance not without significance that so many species of

this type prove themselves capable of tolerating wide variations

in conditions of soil and climate.

FOOTNOTES:

[Footnote 1: In the Superior Zone of the Sierra Nevada I include

all species found above the level of about 1,600 m., considering

this to correspond with the level of 2,000 m. in the Great Atlas.]

[Footnote 2: The name Sierra Nevada is here used in a wide sense,

and is intended to include the Serrania de Ronda, and the other

mountains of Andalusia. Under this head, the plants classed as

‘confined to adjoining regions’ are either common to the Sierra

Nevada and the mountains of Northern Spain, including the Pyrenees,

both Spanish and French, or else are common to the Sierra Nevada

and the mountains of Northern Africa.]

[Footnote 3: The Bulgardagh has been introduced into this table

rather for the sake of contrast than as showing similarity to the

conditions in the Great Atlas. The species classed as ‘confined to

adjoining regions’ are all found in the other mountain districts of

Asia Minor, and it has been necessary to include under the heading

‘Wide-spread Mediterranean’ a large number of Oriental species,

whose western limit is in Greece or Crete. As compared with the Great

Atlas, the number of species common to the western and south-western

parts of Europe is here quite insignificant.]

[Footnote 4: See ‘Spicilegium Floræ Maroccanæ,’ in _Proceedings

of the Linnæan Society_, ‘Botany,’ vol. xvi. parts 93 to

97 inclusive.]

[Footnote 5: The only possible exception to this statement among

the plants enumerated in our list is that entered as _Asparagus

scoparius_, Lowe (?) From the differences between the foliage and

that of other known species it was at first entered as a new species

peculiar to the Atlas. Subsequent comparison with a Madeira specimen

from the late Mr. Lowe suggested their possible identity. Should

this be hereafter verified, the number of endemic species in the

tables given above must be reduced from 75 to 74.]

[Footnote 6: The only apparent exception is _Sagina Linnæi_. This

is habitually a mountain plant; but in Germany it is often seen in

the moorland region, at a level of about 2,500 feet above the sea.]

* * * * *

APPENDIX H.

_Notes on the Geology of the Plain of Marocco and the Great Atlas._

By GEORGE MAW, F.G.S., F.L.S., &c.

Of the Geology of Barbary little information has hitherto been

put on record. The only publications with which I am acquainted

are some notes on the geological features of the district between

Tangier and Marocco in Lieut. Washington’s ‘Geographical Notice

of the Empire of Marocco,’ published in the first volume of the

‘Journal of the Royal Geographical Society;’ a few cursory

remarks on the Marocco Plain by Dr. Hodgkin, in his account of Sir

Moses Montefiore’s ‘Mission to Morocco in 1864;’ a short paper,

by Mr. G. B. Stacey, on the subsidence of the coast near Benghazi,

published in the twenty-third volume of the ‘Quarterly Journal of

the Geological Society;’ a report by M. Mourlon on some rocks and

fossils in the Museum of Brussels, collected in the north-west of

Marocco by M. Desquin, a Belgian engineer, published in Vol. XXX. of

the ‘Bulletin de l’Académie Royale de Belgique,’ for 1870,

to which I shall have further occasion to refer; a geological

memoir, by M. Coquand (‘Bull. de la Soc. Géolog. de France,’

vol. iv. p. 1188), on the environs of Tangier and northern part of

Marocco; and finally, a paper I read before the Geological Society

of London in 1872.

Barbary, with the exception of the immediate neighbourhood of a few

of the ports, has been almost inaccessible to Europeans; and the

extreme jealousy of the Moorish Government with reference to the

mineral riches of the country has hitherto prevented any geological

investigation. In the year 1869 I visited the northern portion of

Marocco, including the Tangier and Tetuan promontory, and during

the spring of 1871 accompanied Dr. Hooker and Mr. Ball to Mogador,

the city of Marocco and the Great Atlas, permission for our visit

having been obtained from the late Sultan through representations

made to the Moorish Government by Lord Granville through Sir John

D. Hay, our Minister Plenipotentiary at Tangier.

The object of the second journey was mainly botanical; and as an

engagement was given by Dr. Hooker that we should not collect

minerals, the opportunities for geological investigation were

very limited.

The observations I was able to make on the structure of the great

chain, which had not been previously ascended by a European,

and of the plain of Marocco, are embodied in the accompanying

section. Stopping for about a fortnight at Tangier, we made several

excursions in the neighbourhood. The western part of the northern

promontory of Marocco, facing the Straits of Gibraltar, consists of

highly-contorted beds of hard courses interstratified with brindled

yellowish sandstones and variegated puce and grey marls, having a

general dip to the south-east, but so twisted about that the dip

and strike are often reversed within a few feet. The country has a

general undulating contour, here and there rising up into ridges of

from 2,000 to 3,000 feet, in which the hard bands weathered out from

the softer strata are strikingly prominent from a great distance.

We observed no palæontological evidence of their age; but,

judging from their resemblance to the cliff-sections near Saffi,

where fossils occur, they are presumably Neocomian or Cretaceous.

Fucoids were collected by M. Coquand in the vicinity of Tangier,

in beds considered by him to be representatives of the Upper Chalk;

but M. Mourlon, referring to the works of Pareto and Studer on

the nummulitic rocks of the Northern Apennines and Switzerland,

inclines to place the Tangier fucoid beds above the nummulitic

horizon, and as part of the Upper Eocene. But near the villages of

Souani and Meharain, a little to the south of Tangier, undoubted

Cretaceous fossils were met with by M. Desquin, including

_Inoceramus_,

_Ostrea Nicaisei_,

_O. syphax_,

_Globiconcha ponderosa_ (?),

_Trigonia_ (casts), and

_Echinodermata_ (undeterminable);

and M. Mourlon concludes that the Tangier promontory consists of

Eocene beds resting on Cretaceous.

The eastern half of the northern promontory, including Tetuan and

Apes’ Hill facing Gibraltar, consists of beds of a different

character, for the most part of a hard metamorphic limestone,

in which dip and strike are very obscure: these may be a southern

extension of the Gibraltar limestone; but I had no opportunity of

tracing the connection to Tetuan.

The late James Smith, of Jordan Hill (in ‘Journal of Geological

Society,’ vol. ii. p. 41), mentions the occurrence of casts of

_Terebratula fimbriata_ and _T. concinna_, belonging to the Lower

Oolite, in the Gibraltar limestone. M. Coquand also assigns to

the Jurassic period the beds in the neighbourhood of Tetuan, and

divides them into four stages, characterised respectively by marls,

dolomites, a calcareous sandstone with the odour of petroleum,

and a lithographic limestone containing siliceous concretions. I

am of opinion that the Tetuan series, ranging with the Gibraltar

limestone, and probably extending far to the south, is separated

from the more recent Cretaceous series to the west and north-west

by a great north and south fault, which divides nearly equally the

Tangier promontory. M. Mourlon, referring to some specimens of shelly

limestone in the Brussels Museum, collected near the river Mhellah

in the district of Ouled Eissa, between Fez and Tetuan, resembling

the Muschelkalk in aspect, and associated with beds resembling

those at Tetuan, considers that they may also be of Jurassic age.

The Tetuan limestone has given rise to enormous beds of brecciated

tufa, on terraces of which the city is built. The flow seems to

have taken place from the hills to the north-west of the city,

and has produced beds of a collective thickness of 60 or 70

feet. This is evidently true tufa, due to aqueous deposition,

and is of a different character from the great calcareous sheet,

to which I shall have occasion further to refer, which shrouds over

the entire plain of Marocco.

Respecting the Mediterranean coast-line of Barbary, I will not add

much to a paper read before the British Association at Liverpool,

in which I remarked on the singular absence of coast-cliffs of any

height. The undulating contour of the land-surface extends down

to the water’s edge, a continuation of the form of the bottom

of the straits without the intervention of cliff-escarpments, from

which I surmised that the present sea-level and coast-line of the

straits had not been of long duration.

Of frequent changes of level on the Barbary coast there is abundant

evidence. The more recent seem to be, first, an elevation of from

60 to 70 feet along the entire coast, implied by the existence of

concrete sand-cliffs with recent shells exactly similar to the raised

beaches of Devon and Cornwall. These occur in Tangier Bay to a height

of 40 feet, resting on the upturned edges of nearly vertical mesozoic

beds; to the south of Cape Spartel, as a long cliff nearly 50 feet

high; as low shoals near Casa Blanca; as a compact cliff about 50

feet high at Saffi, and as a coast-cliff and islands at Mogador,

where the concrete sand-beds attain a height of 60 or 70 feet above

the sea-level. It seems probable that this elevation of coast-line

was coincident with a similar rise, implied by the existence of

concrete sand-cliffs, all along the Spanish and Portuguese coasts,

viz. on the eastern face of Gibraltar, where stratified raised

beaches are seen cropping up at a considerable height from under the

great mass of drift-sand in Catalan Bay; at Cadiz, as low cliffs

40 to 50 feet high, forming a hard coarse freestone of which the

city is built; and also at the Rock of Lisbon, where, at a height

of from 150 to 180 feet, isolated fragments of stratified concrete

sandstone are seen clinging to the sea-escarpment of the older rocks.

The great range of latitude included in this simultaneous coast-rise

suggests the probability that the elevation of similar coast-beds

in Devon and Cornwall may pertain to the same movement.

Judging from the evidence afforded by the coast near Mogador,

a subsequent submergence appears to be taking place. The island

is probably diminishing in bulk; and, from observations made by

M. Beaumier, the French Consul, it appears to have been reduced about

one-fourth in area in twenty years; but whether from denudation or

subsidence is not clear. The sea is, however, sensibly encroaching,

as an old Portuguese fort and some Moorish buildings are now

environed with sand and salt-marsh close to the sea, in a position

where they would not have been built. This submergence of the coast

at Mogador may perhaps be contemporaneous with the subsidence at

Benghazi, Barbary, described by Mr. G. B. Stacey in the twenty-third

volume of the ‘Quarterly Journal of the Geological Society.’

The general absence of cliffs characterises nearly the whole of the

Barbary coast. A few low cliffs occur at scattered intervals west of

Tangier; but from Cape Spartel to Cape Cantin a low monotonous coast

shelves under the waters of the Atlantic, and not a cliff is to be

seen, save an occasional raised beach. After rounding Cape Cantin

the coast trends nearly north and south; and here the first good

coast-section presents itself as a vertical cliff nearly 200 feet

high (fig. 1), consisting of nearly level stratified alternations

of grey and reddish marl, and fine-grained sandstone with beds of

argillaceous carbonate of iron resembling the cement-stone of the

Kimmeridge clay.

At a distance the cliff has a massive rocky aspect due to

the vertical infiltration of tufaceous seams, which support

the softer beds and stand out in prominent masses. The cliffs

continue southwards to Saffi, where I obtained a small series

of fossils from the section represented in fig. 1, amongst which

Mr. Etheridge has determined _Exogyra conica_, _Ostrea Leymerii_,

and _0. Boussingaulti_. He considers the beds to be of Neocomian

age. The hard band c is almost entirely made up of _Exogyra conica_.

I am indebted to the late Mr. Carstensen, H.B.M. Vice-consul at

Mogador, for a specimen of _Ostrea Leymerii_, brought

[Illustration: FIG. 1.

Cliff Section, Saffi.]

In respect of their botanical relationship to neighbouring