ELEPHANTS
In the novel by that clever but contradictious writer, Sam Butler,
entitled "The Way of All Flesh," an amiable and philosophically minded
old gentleman, who pervades the story, states that when one feels
worried or depressed by the incidents of one's daily life, great
comfort may be derived from an hour spent at the Zoological Gardens in
company with the larger mammalia. He ascribes to them a remarkable
soothing influence, and I am inclined to agree with him. I am not
prepared to decide whether the effect is due to the example of
patience under adversity offered by these animals, or whether it is
perhaps their tranquil indifference to everything but food, coupled
with their magnificent success in attaining to such dignity of size,
which imposes upon me and fills me for a brief space with resignation
and a child-like acquiescence in things as they are. The elephant
stands first as a soothing influence, and then the giraffe, the latter
having special powers, due to its beautiful eyes and agreeable
perfume. Sometimes the hippopotamus may diffuse a charm of his own, an
aura of rotund obesity, especially when he is bathing or sleeping; but
there are moments when one has to flee from his presence. I never
could get on very well with rhinoceroses, but the large deer, bison,
and wild cattle have the quality detected by Mr. Butler. So has the
gorgeous, well-grown tiger, in full measure, when he purrs in answer
to one's voice: but the lion is pompous, irritable, and easily upset.
He never purrs. He is unpleasantly and obscurely spotted. He seems to
be afraid of losing his dignity, and to be conscious of the fact that
his reputation--like that of some English officials--depends on the
overpowering wig which he now wears, though his Macedonian forerunner
had no such growth to give an illusive appearance of size and capacity
to his head. However opinions may differ about these things, we will
agree that the elephant (or "Oliphant," as he was called in France 400
years ago) is the most imposing, fascinating, and astonishing of all
animals.
[Illustration: Fig. 6.--The Indian elephant (_Elephas maximus_ or
_indicus_). Observe the small size of its ear-flap.]
At the present day there are two species only of elephant existing on
the earth's surface. These are the Indian (Fig. 6) (called _Elephas
indicus_, but sometimes called _Elephas maximus_ on account of the
priority which belongs to that designation, although the Indian
elephant is smaller than the other), and the African (Fig. 7) (called
_Elephas Africanus_). In the wild state their area of occupation has
become greatly diminished within historic times. The Indian elephant
was hunted in Mesopotamia in the twelfth century B.C., and Egyptian
drawings of the eighteenth dynasty show elephants of this species
brought as tribute by Syrian vassals. To-day the Indian elephant is
confined to certain forests of Hindoostan, Ceylon, Burma, and Siam.
The African elephant extended 100 years ago all over South Africa, and
in the days of the Carthaginians was found near the Mediterranean
shore, whilst in prehistoric (late Pleistocene) times it existed in
the south of Spain and in Sicily. Now it is confined to the more
central and equatorial zone of Africa, and is yearly receding before
the incursions and destructive attacks of civilised man.
[Illustration: Fig. 7.--The African elephant (_Elephas Africanus_)
with rider mounted on its back. The drawing is an enlarged
representation of an ancient Carthaginian coin.]
At no great distance of time before the historic period, earlier,
indeed, than the times of the herdsmen who used polished stone
implements and raised great stone circles, namely, in the late
Pleistocene period, we find that there existed all over Europe and
North Asia and the northern part of America another elephant very
closely allied to the Indian elephant, but having a bow-like outward
curvature of the tusks, their points finally directed towards one
another, and a thick growth of coarse hair all over the body. This is
"the mammoth," the remains of which are found in every river valley in
England, France and Germany, and of which whole carcases are
frequently discovered in Northern Siberia, preserved from decay in the
frozen river gravels and "silt." The ancient cave-men of France used
the fresh tusks of the mammoth killed on the spot for their carvings
and engravings, and from their time to this the ivory of the mammoth
has been, and remains, in constant use. It is estimated that during
the last two centuries at least 100 pairs of mammoths' tusks have been
each year exported from the frozen lands of Siberia. In early mediaeval
times the trade existed, and some ivory carvings and drinking horns of
that age appear to be fashioned from this more ancient ivory.
Already, then, within the human period we find elephants closely
similar to those of our own time, far more numerous and more widely
distributed than in our own day, and happily established all over the
temperate regions of the earth--even in our Thames Valley and in the
forests where London now spreads its smoky brickwork. When we go
further back in time--as the diggings and surveying of modern man
enable us to do--we find other elephants of many different species,
some differing greatly from the three species I have mentioned, and
leading us back by gradual steps to a comparatively small animal,
about the size of a donkey, without the wonderful trunk or the immense
tusks of the later elephants. By the discovery and study of these
earlier forms we have within the last ten years arrived at a knowledge
of the steps by which the elephant acquired in the course of long ages
(millions of years) his "proboscis" (as the Greeks first called it),
and I will later sketch that history.
But now let us first of all note some of the peculiarities of living
elephants and the points by which the two kinds differ from one
another. The most striking fact about the elephant is its enormous
size. It is only exceeded among living animals by whales; it is far
larger than the biggest bull, or rhinoceros, or hippopotamus. A
fair-sized Indian elephant weighs two to three tons (Jumbo, one of the
African species, weighed five), and requires as food 60 lb. of oats,
1-1/2 truss of hay, 1-1/2 truss of corn a day, costing together in
this country about 5_s._; whereas a large cart-horse weighs 15 cwt.,
and requires weekly three trusses of hay and 80 lb. of oats, costing
together 12_s._ or about 1_s._ 8-1/2_d._ a day. It is this which has
proved fatal to the elephant since man took charge of the world. The
elephant requires so much food and takes so many years in growing up
(twenty or more before he is old enough to be put to work), that it is
only in countries where there is a super-abundance of forest in which
he can be allowed to grow to maturity at his own "charges" (so to
speak) that it is worth while to attempt to domesticate and make use
of him. For most purposes three horses are more "handy" than one
elephant. The elephant is caught when he is already grown up, and then
trained. It is as a matter of economy that he is not bred in
confinement, and not because there is any insuperable difficulty in
the matter. Occasionally elephants have bred in menageries.
There is no doubt that the African elephant at the present day grows
to a larger size than the Indian, though it was the opinion of the
Romans of the Empire that the Indian elephant was the more powerful,
courageous, and intelligent of the two. It seems next to impossible to
acquire at the present day either specimens or trustworthy records of
the largest Indian elephants. About 10 ft. 6 ins. at the shoulder
seems to be the maximum, though they are dressed up by their native
owners with platforms and coverings to make them look bigger. In India
the skin of domesticated individuals is polished and carefully
stained, like an old boot, by the assiduity of their guardians, so
that a museum specimen of exceptional size, fit for exhibition and
study, cannot be obtained. On the other hand, the African elephant not
unfrequently exceeds a height of 11 ft. at the shoulder. With some
trouble I obtained one exceeding this measurement direct from East
Africa for the Natural History Museum, where it now stands. It seems
highly probable that this species occasionally exceeds 12 ft. in
height. On the ground, between the great African elephant's fore and
hind legs, in the museum, I placed a stuffed specimen of the smallest
terrestrial mammal--the pigmy shrew-mouse. It is worth while thus
calling to mind that the little animal has practically every separate
bone, muscle, blood-vessel, nerve, and other structure present in the
huge monster compared with it--is, in fact, built closely upon the
same plan, and yet is so much smaller that it is impossible to measure
one by the other. The mouse is only about one fifth the length of the
elephant's eye. According to ancient Oriental fable, the mouse and the
dragon were the only two animals of which the elephant was afraid.
The African elephant has much larger tusks relatively to his size than
the Indian, and both males and females have them, whereas the Indian
female has none. A very fine Indian elephant's tusk weighs from 75 lb.
to 80 lb. The record for an African elephant's tusk was (according to
standard books) 180 lb. But I obtained ten years ago for the museum,
where it now may be seen, an African elephant's tusk weighing 228-1/2
lb. Its fellow weighed a couple of pounds less. It measures 10 ft. 2
in. in length along the curvature. This tusk was recognised by Sir
Henry Stanley's companion, Mr. Jephson, when he was with me in the
museum, as actually one which he had last seen in the centre of
Africa. He told me that he had, in fact, weighed and measured this
tusk in the treasury of Emin Pasha, in Central Africa, when he went
with Stanley to bring Emin down to the coast. As will be remembered,
Emin had no wish to go to the coast, but returned to his province. He
was subsequently attacked and murdered by an Arab chief, who
appropriated his store of ivory, and in the course of time had it
conveyed to the ivory market at Zanzibar. The date of the purchase
there of the museum specimen corresponds with the history given by Mr.
Jephson.
[Illustration: Fig. 8.--The crowns of three "grinders" or molars of
elephants compared. A is that of an extinct mastodon with four
transverse ridges; B is that of the African elephant with nine ridges
in use and ground flat; C is that of the mammoth with sixteen narrow
ridges in use--the rest, some eight in number, are at the left hand of
the figure and not yet in use.]
The African elephant (as could be seen by comparing the small one
living in Regent's Park with its neighbours) has a sloping forehead
graduating into the trunk or proboscis, instead of the broad, upright
brow of the Indian. He also has very much larger ears, which lie
against the shoulders (except when he is greatly excited) like a short
cape or cloak (see Fig. 7). These great ears differ somewhat in shape
in the elephants of different parts of Africa, and local races can be
distinguished by the longer or shorter angle into which the flap is
drawn out. The grinding teeth of the two elephants differ very
markedly, but one must see these in a museum. The grinders are very
large and long (from behind forwards), coming into place one after the
other. Each grinder occupies, when fully in position, the greater part
of one side of the upper or of the lower jaw. They are crossed from
right to left by ridges of enamel, like a series of mountains and
valleys, which gradually wear down by rubbing against those of the
tooth above or below. The biggest grinder of the Indian elephant has
twenty-four of these transverse ridges, whilst that of the African has
only eleven, which are therefore wider apart (see Fig. 8). An extinct
kind of elephant--the mastodon--had only five such ridges on its
biggest grinders, and four or only three on the others. Other
ancestral elephants had quite ordinary-looking grinders, with only two
or three irregular ridges or broad tubercles. Both the Indian and
African elephant have hairless, rough, very hard, wrinkled skins. But
the new-born young are covered with hair, and some Indian elephants
living in cold, mountainous regions appear to retain a certain amount
of hair through life. The mammoth (which agreed with the Indian
elephant in the number of ridges on its grinders and in other points)
lived in quite cold, sub-Arctic conditions, at a time when glaciers
completely covered Scandinavia and the north of our islands as well as
most of Germany. It retained a complete coat of coarse hair throughout
life. The young of our surviving elephants only exhibit transitorily
the family tendency.
The last mammoth probably disappeared from the area which is now Great
Britain about 150,000 years ago. It might be supposed that no elephant
was seen in England again until the creation of "menageries" and
"zoological gardens" within the last two or three hundred years. This,
however, is by no means the case. The Italians in the middle ages, and
through them the French and the rulers of Central Europe, kept
menageries and received as presents, or in connection with their trade
with the East and their relations with Eastern rulers, frequent
specimens of strange beasts from distant lands. Our King Henry I, had
a menagerie at Woodstock, where he kept a porcupine, lions, leopards,
and a camel! The Emperor Charlemagne received in 803 A.D. from Haroun
al Raschid, the Caliph of Bagdad, an elephant named Abulabaz. It was
brought to Aix-la-Chapelle by Isaac the Jew, and died suddenly in 810.
Some four and a half centuries later (in 1257), Louis IX, of France,
returning from the Holy Land, sent as a special and magnificent
present to Henry III, King of England (according to the chronicle of
Matthew Paris), an elephant which was exhibited at the Tower of
London. It was supposed by the chronicler to be the first ever brought
to England, and indeed the first to be taken beyond Italy, for he did
not know of Charlemagne's specimen. In 1591 King Henry IV of France,
wishing to be very polite to Queen Elizabeth of England, and
apparently rather troubled by the expense of keeping the beast
himself, sent to her, having heard that she would like to have it, an
elephant which had been brought from the "Indies" and landed at
Dieppe. He declared it to be the first which had ever come into
France, but presented it to Her Majesty "as I would most willingly
present anything more excellent did I possess it." Thenceforward
elephants were from time to time exhibited at the Tower, together with
lions and other strange beasts acquired by the Crown.
None of these elephants were, however, "the first who ever burst" into
remote Britain after the mammoths had disappeared, and we were
separated from Europe by the geological changes which gave us the
English Channel--La Manche. Though Julius Caesar himself does not
mention it, it is definitely stated by a writer on strategy named
Polyaenus, a friend of the Emperor Marcus Aurelius, but not, I am sorry
to say, an authority to whose statements historians attach any serious
value--that Caesar made use of an elephant armed with iron plates and
carrying on its back a tower full of armed men to terrify the ancient
Britons when he crossed the Thames--an operation which he carried out,
I believe, somewhere between Molesey and Staines.
Elephants are often spoken of as "Ungulates," and classed by
naturalists with the hoofed animals (the odd toed tapirs,
rhinoceroses, and horses, and the even-toed pigs, camel, cattle, and
deer). But there is not much to say in defence of such an association.
The elephants have, as a matter of fact, not got hoofs, and they have
five toes on each foot. The five toes of the front foot have each a
nail, whilst usually only four toes of the hind foot have nails. A
speciality of the elephant is the great circular pad of thick skin
overlying fat and fibrous tissue, which forms the sole of the foot and
bears the animal's enormous weight. This buffer-like development of
the foot existed in some great extinct mammals (the Dinoceras family,
of North America), but is altogether different from the support given
by a horse's hoof or the paired shoe-like hoofs of great cattle or
the three rather elegant hoofed toes of the rhinoceros.
The Indian elephant likes good, solid ground to walk on, and when he
finds himself in a boggy place will seize any large objects
(preferably big branches of trees) and throw them under his feet to
prevent himself sinking in. Occasionally he will remove the stranger
who is riding on his back and make use of him in this way. The
circumference of the African elephant's fore-foot is found by hunters
to be half the animal's height at the shoulder, and is regarded as
furnishing a trustworthy indication of his stature.
The legs of the elephant differ from those of more familiar large
animals in the fact that the ankle and the wrist (the so-called knee
of the horse's foreleg) are not far above the sole of the foot
(resembling man's joints in this respect), whilst the true knee-joint
(called "the stifle" in horses)--instead of being, as in horses, high
up, close against the body, strongly flexed even when at rest, and
obscured by the skin--is far below the body, free and obvious enough.
In fact, the elephant keeps the thigh and the upper arm perpendicular
and in line with the lower segment of the limb when he is standing, so
that the legs are pillar-like. But he bends the joints amply when in
quick movement. The hind legs seen in action resemble, in the
proportions of thigh, foreleg, and foot, and the bending at the knee
and ankle, very closely those of a man walking on "all fours." The
elephant as known in Europe more than 300 years ago was rarely seen in
free movement. He was kept chained up in his stall, resting on his
straight, pillar-like legs and their pad-like feet. And with that
curious avidity for the marvellous which characterized serious writers
in those days to the exclusion of any desire or attempt to ascertain
the truth, it was coolly asserted, and then commonly believed, that
the elephant could not bend his legs. Shakespeare--who, of course, is
merely using a common belief of his time as a chance illustration of
human character--makes Ulysses say (referring to his own stiffness of
carriage) ("Troilus and Cressida," Act II) "The elephant hath joints,
but none for courtesy; his legs are legs for necessity, not for
flexure." An old writer says: "The elephant hath no joints, and, being
unable to lye down, it lieth against a tree, which, the hunters
observing, do saw almost asunder; whereon the beast relying--by the
fall of the tree falls also down itself, and is able to rise no more."
Another old writer (Bartholomew, 1485), says, more correctly: "When
the elephant sitteth he bendeth his feet; he bendeth the hinder legs
right as a man."
A writer of 120 years later in date (Topsell) says: "In the River
Ganges there are blue worms of sixty cubits long having two arms;
these when the elephants come to drink in that river take their trunks
in their hands and pull them off. At the sight of a beautiful woman
elephants leave off all rage and grow meek and gentle. In Africa there
are certain springs of water which, if at any time they dry up, they
are opened and recovered again by the teeth of elephants." The blue
worm of the Ganges referred to is no doubt the crocodile; both in
India and Africa animals coming to the rivers to drink are seized by
lurking crocodiles, who fix their powerful jaws on to the face (snout
or muzzle) of the drinking animal and drag it under the water. Thus
the fable has arisen of the origin of the elephant's trunk as
recounted by Mr. Rudyard Kipling. A young elephant (before the days of
trunks), according to this authority, when drinking at a riverside had
his moderate and well-shaped snout seized by a crocodile. The little
elephant pulled and the crocodile pulled, and by the help of a
friendly python the elephant got the best of it. He extricated himself
from the jaws of death. But, oh! what a difference in his appearance!
His snout was drawn out so as to form that wonderful elongated thing
with two nostrils at the end which we call the elephant's trunk, and
was henceforth transmitted (a first-rate example of an "acquired
character") to future generations! The real origin of the elephant's
trunk is (as I will explain later) a different one from that handed
down to us in the delightful jungle-book. I do not believe in the
hereditary transmission of acquired modifications!
Topsell may or may not be right as to the result produced on elephants
by the sight of a beautiful woman. In Africa the experiment would be a
difficult one, and even in India inconclusive. Topsell seems, however,
to have come across correct information about the digging for water by
an African elephant by the use of his great tusks--those tusks for the
gain of which he is now being rapidly exterminated by man. Serious
drought is frequent in Africa, and a cause of death to thousands of
animals. African elephants, working in company, are known to have
excavated holes in dried-up river beds to the depth of 25 feet in a
single night in search of water. It is probable that the Indian
elephant's tusk would not be of service in such digging, and it is to
be noted that he is rather an inhabitant of high ground and
table-lands than of tropical plains liable to flood and to drought.
The tusk of the Indian elephant has become merely a weapon of attack
for the male, and there are even local breeds in which it is absent in
the males as well as in the females. The mammoth was a near cousin of
the Indian elephant, and inhabited cold uplands and the fringes of
sub-Arctic forests, on which he fed. His tusks were very large, and
curved first outward and then inward at the tips. They would not have
served for heavy digging, and probably were used for forcing a way
through the forest and as a protection to the face and trunk.
The trunk of the elephant was called "a hand" by old writers, and it
seems to have acted in the development of the elephant's intelligence
in the same way as man's hand has in regard to his mental growth,
though in a less degree. The Indian elephant has a single tactile and
grasping projection (sometimes called "a finger") placed above between
the two nostrils at the end of the trunk; the African elephant has one
above and one below. I have seen the elephant pick up with this
wonderful trunk with equal facility a heavy man and then a threepenny
piece.
The intelligence of the elephant is sometimes exaggerated by reports
and stories; sometimes it is not sufficiently appreciated. It is not
fair to compare the intelligence of the elephant with that of the
dog--bred and trained by man for thousands of years. So far as one can
judge, there is no wild animal, excepting the higher apes, which
exhibits so much and such varied intelligence as the elephant. It
appears that from early tertiary times (late Eocene) the ancestors of
elephants have had large brains, whilst, when we go back so far as
this, the ancestors of nearly all other animals had brains a quarter
of the size (and even less in proportion to body-size) which their
modern representatives have. Probably the early possession of a large
brain at a geological period when brains were as a rule small is what
has enabled the elephants not only to survive until to-day, but to
spread over the whole world (except Australia), and to develop an
immense variety and number of individuals throughout the tertiary
series in spite of their ungainly size. It is only the yet bigger
brain of man which (would it were not so!) is now at last driving this
lovable giant, this vast compound of sagacity and strength, out of
existence. The elephant--like man standing on his hind legs--has a
wide survey of things around him owing to his height. He can take time
to allow of cerebral intervention in his actions since he is so large
that he has little cause to be afraid and to hurry. He has a fine and
delicate exploring organ in his trunk, with its hand-like termination;
with this he can, and does, experiment and builds up his individual
knowledge and experience. Elephants act together in the wild state,
aiding one another to uproot trees too large for one to deal with
alone. They readily understand and accept the guidance of man, and
with very small persuasion and teaching execute very dextrous
work--such as the piling of timber. If man had selected the more
intelligent elephants for breeding over a space of a couple of
thousand years a prodigy of animal intelligence would have resulted.
But man has never "bred" the elephant at all.
The Greeks and Romans knew ivory first, and then became acquainted
with the elephant. The island of Elephantina in the Nile was from the
earliest times a seat of trade in the ivory tusks of the African
elephant, and so acquired its name. Herodotus is the first to mention
the elephant itself; Homer only refers to the ivory by the word
"elephas." Aristotle in this, as in other matters, is more correct
than later writers. He probably received first-hand information about
the elephant from Alexander and some of his men after their Indian
expedition. The Romans had an unpleasant first personal experience of
elephants when Pyrrhus, King of Epirus, landed a number with his army
and put the Roman soldiers to flight. But the Romans then, and
continually in after-times, showed their cool heads and sound judgment
in a certain contempt for elephants as engines of war. They soon
learned to dig pits on the battlefield to entrap the great beasts, and
they deliberately made for the elephants' trunks, hewing them through
with their swords, so that the agonised and maddened creatures turned
round and trampled down the troops of their own side. The Romans only
used them subsequently to terrify barbaric people, and as features in
military processions. But Eastern nations used them extensively in
war. In A.D. 217 Antiochus the Great brought 217 elephants in his army
against 73 employed by Ptolemy, at what was called "the Battle of the
Elephants." The battle commenced by the charging head to head of the
opposing elephants and the discharge of arrows, spears and stones by
the men in the towers on their backs.
An interesting question has been raised as to whether the elephants
used by the Carthaginians were the African species or the Indian.
There is no doubt that the elephants of Pyrrhus and those known to
Alexander were the Indian, though they were taken in those days much
to the West of India, namely, in Mesopotamia, and it would not have
been difficult for the Carthaginians to convey Indian elephants, which
had certainly been brought as far as Egypt, along the Mediterranean
coast. An unfounded prejudice as to the want of docility of the
African elephant has favoured the notion that the Carthaginians used
the Indian elephant. As a matter of fact, no one in modern times has
tried to train the African elephant, except here and there in a
zoological garden. Probably the Indian "mahout," or elephant trainer
could, if he were put to it, do as much with an African as he does
with an Indian elephant. It would be an interesting experiment. In the
next place, there is decisive evidence that it was the African
elephant which the Carthaginians used, since we have a Carthaginian
coin (Fig. 7) on which is beautifully represented--in unmistakable
modelling--the African elephant, with his large triangular cape-like
ears and his sloping forehead. In the time of Hannibal there were
stables for over 300 of these elephants at Carthage, and he took fifty
with him to the South of France with his army for the Italian
invasion. He only got thirty-seven safely over the Rhone, and all but
a dozen or so died in the terrible passage of the Alps. After the
battle of Trebia he had only eight left, and when he had crossed the
Apennines there was only one still alive. On this Hannibal himself
rode.
Since the period when the white chalk which now forms our cliffs and
hills was deposited at the bottom of a vast and deep ocean--the sea
bottom has been raised, the chalk has emerged and risen on the top of
hills to 800 feet in height in our own islands, and to ten times that
height elsewhere, and during that process sands and clays and shelly
gravels have been deposited to the thickness of some 2,800 feet by
seas and estuaries and lakes, which have come and gone on the face of
Europe and of other parts of the world as it has slowly sunk and
slowly risen again. The last 200 feet or so of deposits we call the
Pleistocene or Quaternary; the rest are known as the Tertiary strata.
They are only a small part of the total thickness of aqueous deposit
of stratified rock--which amounts to 60,000 feet more before the
earliest remains of life in the Cambrian beds are reached, whilst
older than, and therefore below this, we have another 50,000 feet of
water-made rock which yields no fossils--no remains of living things,
though living things were certainly there! Our little layer of
Tertiary strata on the top is, however, very important. It took
several million years in forming, although it is only one-fortieth of
the whole thickness of aqueous deposit on the crust of the earth. We
divide it into Pliocene, Miocene, and Eocene, and each of these into
upper, middle, and lower, the Eocene being the oldest. Our London clay
and Woolwich sands are lower Eocene; there is a good deal of Miocene
in Switzerland and Germany, whilst the Pliocene is represented by
whole provinces of Italy, parts of central France, and by the White
and Red "crags" of Suffolk.[5]
[Illustration: Fig. 9.--Skeleton of the Indian elephant. Only four
toes are visible, the fifth concealed owing to the view from the
side.]
It is during this Tertiary period that the mammals--the warm-blooded,
hairy quadrupeds, which suckle their young--have developed (they had
come into existence a good deal earlier), and we find the remains of
ancestral forms of the living kinds of cattle, pigs, horses,
rhinoceroses, tapirs, elephants, lions, wolves, bears, etc., embedded
in the successive layers of Tertiary deposits. Naturally enough, those
most like the present animals are found in late Pliocene, and those
which are close to the common ancestors of many of the later kinds are
found in the Eocene, whilst we also find, at various levels of the
Tertiary deposit, remains of side-branches of the mammalian pedigree,
which, though including very powerful and remarkable beasts, have left
no line of descent to represent them at the present day. We have been
able to trace the great modern one-toed horses, zebras, and asses,
with their complicated pattern of grinding-teeth back by quite gradual
steps (represented by the bones and teeth of fossil kinds of horses),
to smaller three-toed animals with simpler tuberculated teeth, and
even, without any marked break in the series, to a small Eocene animal
(not bigger than a spaniel) with four equal-sized toes on its front
foot, and three on its hind foot. We know, too, a less direct series
of intermediate forms leading beyond this to an animal with five toes
on each foot and "typical" teeth. In fact, no one doubts that
(leaving aside a few difficult and doubtful cases) all such big
existing mammals, as I mentioned above, as well as monkeys and man,
are derived from small mammals--intermediate in most ways between a
hedgehog and a pig--which flourished in very early Eocene times, and
had five toes on each foot, and "a typical dentition." Even the
elephants came from such a small ancestral form. The common notion
that the extinct forerunners of existing animals were much bigger than
recent kinds, and even gigantic, is not in accordance with fact. Some
extinct animals were of very great size--especially the great reptiles
of the period long before the Tertiaries, and before the chalk. But
the recent horse, the recent elephant, the giraffe, the lions, bears,
and others, are bigger--some much bigger--than the ancestral forms, to
which we can trace them by the wonderfully preserved and wonderfully
collected and worked-out fossilised bones discovered in the successive
layers of the Pliocene, Miocene, and Eocene strata, leading us as we
descend to more primitive, simplified, and smaller ancestors.
It is easy to understand the initial character of the foot of the
early ancestral mammals. It had five toes. By the suppression or
atrophy of first the innermost toe, then of the outermost, you find
that mammals may first acquire four toes only, and then only three,
and by repeating the process the toes may be reduced to two, or right
away to one, the original middle toe. There is no special difficulty
about tracing back the elephants in so far as this matter is
concerned, since they have kept (like man and some other mammals) the
full typical complement of five toes on each foot.
But I must explain a little more at length what was the "typical
dentition,"--that is to say, the exact number and form of the teeth in
each half of the upper and the lower jaw of the early mammalian
ancestor of lower Eocene times, or just before. The jaws were drawn
out into a snout or muzzle, an elongated, protruding "face," as in a
dog or deer or hedgehog, and there were numerous teeth set in a row
along the gums of the upper and the lower jaw. The teeth were the same
in number, in upper and in lower jaw, and so formed as to work
together, those of the lower jaw shutting as a rule just a little in
front of the corresponding teeth of the upper jaw. There were above
and below, in front, six small chisel-like teeth, which we call "the
incisors." At the corner of the mouth above and below on each side
flanking these was a corner tooth, or dog-tooth, a little bigger than
the incisors, and more pointed and projecting. These we call "the
canines," four in all. Then we turn the corner of the mouth-front, as
it were, and come to the "grinders," cheek-teeth or molars. These are
placed in a row along each half of upper and lower jaw. In our early
mammalian ancestor they were seven in number, with broader crowns than
the peg-like incisors and canines, the bright polished enamel of the
crown being raised up into two, three or four cone-like prominences.
The back grinders are broader and bigger than those nearer the
dog-tooth. The three hindermost grinders in each half of each jaw are
not replaced by "second" teeth, whilst all the other teeth are.
[Illustration: Fig. 10.--The teeth in the upper and lower jaw-bone of
the common pig--drawn from photographs. A and B represent the right
half of the lower jaw (A) and the right half of the upper jaw (B) seen
in horizontal position. _Inc._ are the incisors or chisel-like front
teeth, three in number, in each half of each jaw and marked 1, 2, 3.
_C_ marks the canine or dog-tooth, which here grows to be a large
tusk. The molars, "grinders," or cheek teeth are marked 1 to 7. Figs.
C and D give a side view of the left halves of the upper (C) and of
the lower jaw-bone (D), with the teeth in place. The bone has been
partly cut away so as to show the fangs or roots of the teeth, which
are double in the molars, and even threefold in molar No. 7. The
explanation of the lettering is the same as that given for Figs. A and
B. The letter _p_ in Fig. B points to a "foramen" or hole in the upper
jaw-bone. These drawings are introduced here as showing the _complete_
number of teeth which the ancestor of pigs, goats, elephants, dogs,
tigers, men, and even whales possessed. The reduction in number and
the alteration in the shape of the primitive full set of teeth is
referred to in the present chapter on "Elephants," and in those on
"Vegetarians and their Teeth" (p. 102), and on "A Strange Extinct
Beast" (p. 92).]
Now this typical set of teeth--consisting of twenty-eight grinders,
four canines, and twelve incisors--is not found complete in many
mammals at the present day, though it is found more frequently as we
go back to earlier strata.[6] Though some mammals have kept close to
the original number, they have developed peculiar shape and qualities
in some of the teeth as well as changes in size. The common pig still
keeps the typical number (Fig. 10), but he has developed the corner
teeth or canines into enormous tusks both in the upper and lower jaw,
and the more anterior grinders have become quite minute. The cats
(lions and tigers included) have kept the full number of incisors (see
Figs. 21 and 22, pp. 103, 104); they have developed the four canines
into enormous and deadly stabbing "fangs," and they have lost all the
grinders but three in each half of the lower jaw and four in each half
of the upper jaw (twelve instead of twenty-eight), and these have
become sharp-edged so as to be scissor-like in their action, instead
of crushing or grinding. Man and the old-world monkeys have lost an
incisor in each half of each jaw (see Pls. VI and VII); they retain
the canines, but have only five molars in each half of each jaw
(twenty in all instead of twenty-eight). Most of the mammals--whatever
change of number and shape has befallen their teeth in adaptation to
their different requirements as to the kind of food and mode of
getting it--have retained a good long pair of jaws and a snout or
muzzle consisting of nose, upper jaw, and lower jaw, projecting well
in front of the eyes and brain-case. Man is remarkable as an
exception. In the higher races of men the jaws are shorter than in the
lower races, and project but very little beyond the vertical plane of
the eyes, whilst the nose projects beyond the lips. Another exception
is the elephant. This is most obvious when the prepared bony skull and
lower jaw are examined, but can be sufficiently clearly seen in the
living animal. The lower jaw and the part of the upper jaw against
which it and its grinders play is extraordinarily short and small. The
elephant has, in fact, no projecting bony jaw at all, no bony snout,
its chin does not project more than that of an old man, and even the
part of the upper jaw into which its great tusks are set does not bend
forward far from the perpendicular (Fig. 9).
[Illustration: Fig. 11.--A reconstruction of the extinct American
mastodon (_Mastodon ohioticus_) from a drawing by Prof. Osborne. Other
extinct species of mastodon are found in Europe.]
[Illustration: Fig. 12.--A. Skull, and B. restored outline of the head
of the long-jawed extinct elephant called Tetrabelodon--the name
referring to its four large tusks--two above and two below.]
The elephant (see Fig. 9) has no sign of the six little front teeth
(incisors) above and below which we find in the typical dentition and
in many living mammals, nor of the corner teeth (dog-teeth, or
canines). In the upper jaw in front there is the one huge tusk on
each side, and in the lower jaw no front teeth at all! Then as to the
grinders. In the elephant these are enormous, with many transverse
ridges on the elongated crown, and so big that there is only room for
one at a time in each half of upper and lower jaw. Six of these
succeed one another in each half of each jaw, and correspond (though
greatly altered) to six of the seven grinders of the typical
dentition. Are there amongst older fossil elephants and animals like
elephants any which have an intermediate condition of the teeth,
connecting the extremely peculiar teeth of the modern elephants with
the typical dentition such as is approached by the pig, the dog, the
tapir, and the hedgehog? There are such links. We know a great many
elephants from Pleistocene and Pliocene strata--some from European
localities, more from India, and some from America. A little elephant
not more than 3 feet high when adult is found fossil in the island of
Malta; other species were a little larger than the living African
elephant. Whilst the Indian elephant has as many as twenty-four
cross-ridges on its biggest grinding tooth (Fig. 8) there is a fossil
kind which has only six such ridges. But besides true elephants we
know from the Pliocene, Miocene, and Upper Eocene of the old world,
the remains of elephant-like creatures (some as big as true
elephants), which are distinguished by the name "Mastodon" (Fig. 11).
And, in fact, we are conducted through a series of changes of form by
ancient elephant-like creatures which are of older and older date as
we pass along the series, and are known as (1) Mastodon, (2)
Tetrabelodon, (3) Palaeomastodon, (4) Meritherium, until we come to
something approaching the general form of skull and skeleton and the
typical dentition of the early mammalian ancestor. Mastodons of
several species are found in Pliocene strata in Europe and Asia;
detached teeth are found in Suffolk. One species actually survived
(why, we do not know) in North America into the early human period,
and whole skeletons of it are dug out from the morasses such as that
of "Big-bone Lick." The Mastodons had a longer jaw and face than the
elephants, though closely allied to them. They bring one nearer to
ordinary mammals in that fact, and also in having (when young) two
front teeth or incisors in the lower jaw. Their grinders had the
crowns less elongated than those of the elephants, and there were only
five cross-ridges--on the biggest--and these ridges tend to divide
into separate cones (Fig. 8). So here, too, we are approaching the
ordinary mammals, of which we may keep the pig and the tapir in mind
as samples. But the Mastodons still had the great trunk and huge tusks
of the elephants.
Next we must look at Tetrabelodon (Fig. 12), and it is this creature
which has really revealed the history of the strange metamorphosis by
which elephants were produced. The Tetrabelodon is known as "the
long-jawed mastodon," because, as was shown in a wonderfully
well-preserved skeleton from the lower Pliocene of the centre of
France, set up in the Paris Museum, it had a lower jaw of enormous
length, ending in two large horizontally directed teeth (Fig. 12).
Instead of a lower jaw a foot long, as in an elephant or in the common
kind of mastodon--this long-jawed kind had a lower jaw 5 feet or 6
feet long! The tusks of the upper jaw were large, and nearly
horizontal in direction, bent downwards a little on each side of the
long lower jaw. This lower jaw seemed incomprehensible, almost a
monstrosity--until it occurred to me that it exactly corresponds to
the elongated upper lip and nose which we call the elephant's
trunk--and that the trunk of "Tetrabelodon" must have rested on his
long lower jaw. In descending to Tetrabelodon we leave behind us the
elephants with hanging unsupported trunk; the lower jaw here is of
sufficient length to support the great trunk. When the lower jaw
shortened in the later mastodons and elephants the trunk did not
shorten too, but remained free and depending, capable of large
movement and of grasping with its extremity. Photographs, casts, and
actual specimens of the extraordinary skull of the long-jawed mastodon
or Tetrabelodon and of the creatures mentioned below may be seen in
the Natural History Museum.
Lastly we have the wonderful series of discoveries made about twelve
years ago by Dr. Andrews (of the Natural History Museum) of
elephant-like creatures in the upper Eocene of the Fayoum Desert of
Egypt. Palaeomastodon (the name given by Dr. Andrews to one of them) is
a "pig-like" mastodon, with an elongated, bony face, the tusks of
moderate size, and the lower jaw not projecting more than a few inches
beyond them, so that the proboscis is quite short and rests well on it
(Fig. 13). This animal had six moderate sized grinders (molars or
cheek-teeth) on each side of each jaw in position simultaneously, as
may be seen in the complete skull shown in Fig. 14. Of other teeth it
had only the two moderate-sized front tusks above and two very big,
chisel-like "incisors" in the front of the lower jaw. Exactly how
these were used and for what food no one has yet made out.
[Illustration: Fig. 13.--Head of the ancestral elephant--Palaeomastodon--as
it appeared in life. It shows, as compared with the earlier ancestor,
an elongation both of the snout and the lower jaws. The tusk in the
upper jaw has increased in size, but is still small as compared with
that of later elephants. (After a drawing by Prof. Osborne.)]
[Illustration: Fig. 14.--Restored model of the skull and lower jaw of
the ancestral elephant Palaeomastodon from the upper Eocene strata of
the Fayoum Desert, Egypt. It shows the six molar teeth of the upper
and lower jaw (left side), the tusk-like upper incisors and the large
chisel-like lower incisors in front.]
The remains, which finally bring the elephants into line with the
ordinary mammals with typical dentition, were discovered also by Dr.
Andrews and named "Meritherium" by him, signifying "the beast of the
Lake Meris." This creature is not bigger than a tapir, and had the
shape of head and face which we see in that and the ordinary hoofed
animals (Fig. 15). It had no trunk, and whilst it had six small and
simplified mastodon-like grinders in each half of each jaw, it had six
incisors in the upper jaw and a canine or corner tooth on each side.
In the lower jaw there were only two large incisors besides the
cheek-teeth or grinders. Not the least interesting point about
Meritherium is that it tells us which of the front upper teeth have
become the huge tusks of the later elephants. Counting from the middle
line there are in Meritherium three incisors right and three left. The
second of these upper teeth on each side is much larger than the
others. It is this (seen in Fig. 15) which has grown larger and larger
in later descendants of this primitive form and become the elephant's
tusk, whilst all the others have disappeared.
[Illustration: Fig. 15.--Head of the early ancestor of
elephants--Meritherium--as it appeared in life. Observe the absence of
a trunk and the enlarged front tooth in the upper jaw, which is
converted in later members of the elephant-stock or line of descent
into the great tusk. (After a drawing by Prof. Osborne.)]
We now know the complete series of steps connecting elephants with
ordinary trunkless, tuskless mammals. The transition from the "beast
of Meris" on the one hand to the common typidentate mammalian
ancestor, and on the other hand to the elephants, is easy, and
requires no effort of the imagination. His short muzzle (upper and
lower jaw), first elongated step by step to a considerable length,
giving us Palaeomastodon (Fig. 13). Then the lower jaw shrunk and
became shorter than it was at the start, and the rest of the muzzle
(the front part of the upper jaw, carrying with it the nostrils),
drooped and became the mobile muscular elephant's trunk!
FOOTNOTES:
[Footnote 5: I am inclined to think that the line between Pliocene and
Pleistocene or Quaternary ought, in this country, to be drawn between
the White and Red Crag of Suffolk. Glacial conditions set in and were
recurrent from the commencement of the Red Crag deposit onwards.]
[Footnote 6: Mammals having the number and form of teeth which I have
just described as typical--or such modification of it as can easily be
produced by suppression of some teeth and enlargement of others--are
called Typidentata. On the other hand, the whales, the sloths,
ant-eaters, and armadilloes, as also the Marsupials, are called
Variodentata, because we cannot derive their teeth from those of the
Typidentate ancestor. They form lines of descent which separated from
the other mammals before the Typidentate ancestor of all, except the
groups just named, was evolved.]