In a few paragraphs a picture of the lush vegetation and swa_A Short History of the World

reptiles of that first great summer of life, the Mesozoic period, has

been sketched. But while the Dinosaurs lorded it over the hot selvas

and marshy plains and the Pterodactyls filled the forests with their

flutterings and possibly with shrieks and croakings as they pursued the

humming insect life of the still flowerless shrubs and trees, some less

conspicuous and less abundant forms upon the margins of this abounding

life were acquiring certain powers and learning certain lessons of

endurance, that were to be of the utmost value to their race when at

last the smiling generosity of sun and earth began to fade.

A group of tribes and genera of hopping reptiles, small creatures of

the dinosaur type, seem to have been pushed by competition and the

pursuit of their enemies towards the alternatives of extinction or

adaptation to colder conditions in the higher hills or by the sea.

Among these distressed tribes there was developed a new type of

scale—scales that were elongated into quill-like forms and that

presently branched into the crude beginnings of feathers. These

quill-like scales layover one another and formed a heat-retaining

covering more efficient than any reptilian covering that had hitherto

existed. So they permitted an invasion of colder regions that were

otherwise uninhabited. Perhaps simultaneously with these changes there

arose in these creatures a greater solicitude for their eggs. Most

reptiles are apparently quite careless about their eggs, which are left

for sun and season to hatch. But some of the varieties upon this new

branch of the tree of life were acquiring a habit of guarding their

eggs and keeping them warm with the warmth of their bodies.

With these adaptations to cold other internal modifications were going

on that made these creatures, the primitive birds, warm-blooded and

independent of basking. The very earliest birds seem to have been

seabirds living upon fish, and their fore limbs were not wings but

paddles rather after the penguin type. That peculiarly primitive bird,

the New Zealand Ki-Wi, has feathers of a very simple sort, and neither

flies nor appears to be descended from flying ancestors. In the

development of the birds, feathers came before wings. But once the

feather was developed the possibility of making a light spread of

feathers led inevitably to the wing. We know of the fossil remains of

one bird at least which had reptilian teeth in its jaw and a long

reptilian tail, but which also had a true bird’s wing and which

certainly flew and held its own among the pterodactyls of the Mesozoic

time. Nevertheless birds were neither varied nor abundant in Mesozoic

times. If a man could go back to typical Mesozoic country, he might

walk for days and never see or hear such a thing as a bird, though he

would see a great abundance of pterodactyls and insects among the

fronds and reeds.

FOSSIL OF THE ARCHEOPTERYX; ONE OF THE EARLIEST BIRDS

_Nat. Hist. Mus._

And another thing he would probably never see, and that would be any

sign of a mammal. Probably the first mammals were in existence

millions of years before the first thing one could call a bird, but

they were altogether too small and obscure and remote for attention.

HESPERORNIS IN ITS NATIVE SEAS

The earliest mammals, like the earliest birds, were creatures driven by

competition and pursuit into a life of hardship and adaptation to cold.

With them also the scale became quill-like, and was developed into a

heat-retaining covering; and they too underwent modifications, similar

in kind though different in detail, to become warm-blooded and

independent of basking. Instead of feathers they developed hairs, and

instead of guarding and incubating their eggs they kept them warm and

safe by retaining them inside their bodies until they were almost

mature. Most of them became altogether vivaparous and brought their

young into the world alive. And even after their young were born they

tended to maintain a protective and nutritive association with them.

Most but not all mammals to-day have mammæ and suckle their young. Two

mammals still live which lay eggs and which have not proper mammæ,

though they nourish their young by a nutritive secretion of the under

skin; these are the duck-billed platypus and the echidna. The echidna

lays leathery eggs and then puts them into a pouch under its belly, and

so carries them about warm and safe until they hatch.

But just as a visitor to the Mesozoic world might have searched for

days and weeks before finding a bird, so, unless he knew exactly where

to go and look, he might have searched in vain for any traces of a

mammal. Both birds and mammals would have seemed very eccentric and

secondary and unimportant creatures in Mesozoic times.

THE KI-WI, APTERYX, STILL FOUND IN NEW ZEALAND

_Photo: Autotype Fine Art Co._

SLAB OF LOWER PLIOCENE MARL

Discovered in Greece; it is rich in fossilized bones of early mammals

The Age of Reptiles lasted, it is now guessed, eighty million years.

Had any quasi-human intelligence been watching the world through that

inconceivable length of time, how safe and eternal the sunshine and

abundance must have seemed, how assured the wallowing prosperity of the

dinosaurs and the flapping abundance of the flying lizards! And then

the mysterious rhythms and accumulating forces of the universe began to

turn against that quasi-eternal stability. That run of luck for life

was running out. Age by age, myriad of years after myriad of years,

with halts no doubt and retrogressions, came a change towards hardship

and extreme conditions, came great alterations of level and great

redistributions of mountain and sea. We find one thing in the Record

of the Rocks during the decadence of the long Mesozoic age of

prosperity that is very significant of steadily sustained changes of

condition, and that is a violent fluctuation of living forms and the

appearance of new and strange species. Under the gathering threat of

extinction the older orders and genera are displaying their utmost

capacity for variation and adaptation. The Ammonites for example in

these last pages of the Mesozoic chapter exhibit a multitude of

fantastic forms. Under settled conditions there is no encouragement

for novelties; they do not develop, they are suppressed; what is best

adapted is already there. Under novel conditions it is the ordinary

type that suffers, and the novelty that may have a better chance to

survive and establish itself....

There comes a break in the Record of the Rocks that may represent

several million years. There is a veil here still, over even the

outline of the history of life. When it lifts again, the Age of

Reptiles is at an end; the Dinosaurs, the Plesiosaurs and Ichthyosaurs,

the Pterodactyls, the innumerable genera and species of Ammonite have

all gone absolutely. In all their stupendous variety they have died

out and left no descendants. The cold has killed them. All their

final variations were insufficient; they had never hit upon survival

conditions. The world had passed through a phase of extreme conditions

beyond their powers of endurance, a slow and complete massacre of

Mesozoic life has occurred, and we find now a new scene, a new and

hardier flora, and a new and hardier fauna in possession of the world.

It is still a bleak and impoverished scene with which this new volume

of the book of life begins. The cycads and tropical conifers have given

place very largely to trees that shed their leaves to avoid destruction

by the snows of winter and to flowering plants and shrubs, and where

there was formerly a profusion of reptiles, an increasing variety of

birds and mammals is entering into their inheritance.

VIII

THE AGE OF MAMMALS

The opening of the next great period in the life of the earth, the

Cainozoic period, was a period of upheaval and extreme volcanic

activity. Now it was that the vast masses of the Alps and Himalayas and

the mountain backbone of the Rockies and Andes were thrust up, and that

the rude outlines of our present oceans and continents appeared. The

map of the world begins to display a first dim resemblance to the map

of to-day. It is estimated now that between forty and eighty million

years have elapsed from the beginnings of the Cainozoic period to the

present time.

At the outset of the Cainozoic period the climate of the world was

austere. It grew generally warmer until a fresh phase of great

abundance was reached, after which conditions grew hard again and the

earth passed into a series of extremely cold cycles, the Glacial Ages,

from which apparently it is now slowly emerging.

But we do not know sufficient of the causes of climatic change at

present to forecast the possible fluctuations of climatic conditions

that lie before us. We may be moving towards increasing sunshine or

lapsing towards another glacial age; volcanic activity and the upheaval

of mountain masses may be increasing or diminishing; we do not know; we

lack sufficient science.

With the opening of this period the grasses appear; for the first time

there is pasture in the world; and with the full development of the

once obscure mammalian type, appear a number of interesting grazing

animals and of carnivorous types which prey upon these.

At first these early mammals seem to differ only in a few characters

from the great herbivorous and carnivorous reptiles that ages before

had flourished and then vanished from the earth. A careless observer

might suppose that in this second long age of warmth and plenty that

was now beginning, nature was merely repeating the first, with

herbivorous and carnivorous mammals to parallel the herbivorous and

carnivorous dinosaurs, with birds replacing pterodactyls and so on.

But this would be an altogether superficial comparison. The variety of

the universe is infinite and incessant; it progresses eternally;

history never repeats itself and no parallels are precisely true. The

differences between the life of the Cainozoic and Mesozoic periods are

far profounder than the resemblances.

A MAMMAL OF THE EARLY CAINOZOIC PERIOD

The Titanotherum (Brontops) Robustum

The most fundamental of all these differences lies in the mental life

of the two periods. It arises essentially out of the continuing

contact of parent and offspring which distinguishes mammalian and in a

lesser degree bird life, from the life of the reptile. With very few

exceptions the reptile abandons its egg to hatch alone. The young

reptile has no knowledge whatever of its parent; its mental life, such

as it is, begins and ends with its own experiences. It may tolerate the

existence of its fellows but it has no communication with them; it

never imitates, never learns from them, is incapable of concerted

action with them. Its life is that of an isolated individual. But

with the suckling and cherishing of young which was distinctive of the

new mammalian and avian strains arose the possibility of learning by

imitation, of communication, by warning cries and other concerted

action, of mutual control and instruction. A teachable type of life

had come into the world.

The earliest mammals of the Cainozoic period are but little superior in

brain size to the more active carnivorous dinosaurs, but as we read on

through the record towards modern times we find, in every tribe and

race of the mammalian animals, a steady universal increase in brain

capacity. For instance we find at a comparatively early stage that

rhinoceros-like beasts appear. There is a creature, the Titanotherium,

which lived in the earliest division of this period. It was probably

very like a modern rhinoceros in its habits and needs. But its brain

capacity was not one tenth that of its living successor.

The earlier mammals probably parted from their offspring as soon as

suckling was over, but, once the capacity for mutual understanding has

arisen, the advantages of continuing the association are very great;

and we presently find a number of mammalian species displaying the

beginnings of a true social life and keeping together in herds, packs

and flocks, watching each other, imitating each other, taking warning

from each other’s acts and cries. This is something that the world had

not seen before among vertebrated animals. Reptiles and fish may no

doubt be found in swarms and shoals; they have been hatched in

quantities and similar conditions have kept them together, but in the

case of the social and gregarious mammals the association arises not

simply from a community of external forces, it is sustained by an inner

impulse. They are not merely like one another and so found in the same

places at the same times; they like one another and so they keep

together.

STENOMYLUS HITCHCOCKI--A GIRAFFE-CAMEL

STENOMYLUS HITCHCOCKI—A GIRAFFE-CAMEL

_Nat. Hist. Mus._

SKELETON OF PROTOHIPPUS VENTICOLUS—EARLY HORSE

SKELETON OF PROTOHIPPUS VENTICOLUS--EARLY HORSE

_Nat. Hist. Mus._

This difference between the reptile world and the world of our human

minds is one our sympathies seem unable to pass. We cannot conceive in

ourselves the swift uncomplicated urgency of a reptile’s instinctive

motives, its appetites, fears and hates. We cannot understand them in

their simplicity because all our motives are complicated; our’s are

balances and resultants and not simple urgencies. But the mammals and

birds have self-restraint and consideration for other individuals, a

social appeal, a self- control that is, at its lower level, after our

own fashion. We can in consequence establish relations with almost all

sorts of them. When they suffer they utter cries and make movements

that rouse our feelings. We can make understanding pets of them with a

mutual recognition. They can be tamed to self-restraint towards us,

domesticated and taught.

COMPARATIVE SIZES OF BRAINS OF RHINOCEROS AND DINOCERAS

_Nat. Hist. Mus._

That unusual growth of brain which is the central fact of Cainozoic

times marks a new communication and interdependence of individuals. It

foreshadows the development of human societies of which we shall soon

be telling.

As the Cainozoic period unrolled, the resemblance of its flora and

fauna to the plants and animals that inhabit the world to-day

increased. The big clumsy Uintatheres and Titanotheres, the

Entelodonts and Hyracodons, big clumsy brutes like nothing living,

disappeared. On the other hand a series of forms led up by steady

degrees from grotesque and clumsy predecessors to the giraffes, camels,

horses, elephants, deer, dogs and lions and tigers of the existing

world. The evolution of the horse is particularly legible upon the

geological record. We have a fairly complete series of forms from a

small tapir-like ancestor in the early Cainozoic. Another line of

development that has now been pieced together with some precision is

that of the llamas and camels.

MONKEYS, APES AND SUB-MEN

Naturalists divide the class _Mammalia_ into a number of orders. At the

head of these is the order _Primates_, which includes the lemurs, the

monkeys, apes and man. Their classification was based originally upon

anatomical resemblances and took no account of any mental qualities.

Now the past history of the Primates is one very difficult to decipher

in the geological record. They are for the most part animals which

live in forests like the lemurs and monkeys or in bare rocky places

like the baboons. They are rarely drowned and covered up by sediment,

nor are most of them very numerous species, and so they do not figure

so largely among the fossils as the ancestors of the horses, camels and

so forth do. But we know that quite early in the Cainozoic period,

that is to say some forty million years ago or so, primitive monkeys

and lemuroid creatures had appeared, poorer in brain and not so

specialized as their later successors.

The great world summer of the middle Cainozoic period drew at last to

an end. It was to follow those other two great summers in the history

of life, the summer of the Coal Swamps and the vast summer of the Age

of Reptiles. Once more the earth spun towards an ice age. The world

chilled, grew milder for a time and chilled again. In the warm past

hippopotami had wallowed through a lush sub-tropical vegetation, and a

tremendous tiger with fangs like sabres, the sabre-toothed tiger, had

hunted its prey where now the journalists of Fleet Street go to and

fro. Now came a bleaker age and still bleaker ages. A great weeding

and extinction of species occurred. A woolly rhinoceros, adapted to a

cold climate, and the mammoth, a big woolly cousin of the elephants,

the Arctic musk ox and the reindeer passed across the scene. Then

century by century the Arctic ice cap, the wintry death of the great

Ice Age, crept southward. In England it came almost down to the

Thames, in America it reached Ohio. There would be warmer spells of a

few thousand years and relapses towards a bitterer cold.

Geologists talk of these wintry phases as the First, Second, Third and

Fourth Glacial Ages, and of the interludes as Interglacial periods. We

live to-day in a world that is still impoverished and scarred by that

terrible winter. The First Glacial Age was coming on 600,000 years

ago; the Fourth Glacial Age reached its bitterest some fifty thousand

years ago. And it was amidst the snows of this long universal winter

that the first man-like beings lived upon our planet.

A MAMMOTH

By the middle Cainozoic period there have appeared various apes with

many quasi-human attributes of the jaws and leg bones, but it is only

as we approach these Glacial Ages that we find traces of creatures that

we can speak of as “almost human.” These traces are not bones but

implements. In Europe, in deposits of this period, between half a

million and a million years old, we find flints and stones that have

evidently been chipped intentionally by some handy creature desirous of

hammering, scraping or fighting with the sharpened edge. These things

have been called “Eoliths” (dawn stones). In Europe there are no bones

nor other remains of the creature which made these objects, simply the

objects themselves. For all the certainty we have it may have been

some entirely un-human but intelligent monkey. But at Trinil in Java,

in accumulations of this age, a piece of a skull and various teeth and

bones have been found of a sort of ape man, with a brain case bigger

than that of any living apes, which seems to have walked erect. This

creature is now called _Pithecanthropus erectus_, the walking ape man,

and the little trayful of its bones is the only help our imaginations

have as yet in figuring to, ourselves the makers of the Eoliths.

FLINT IMPLEMENTS FOUND IN PILTDOWN REGION

_Nat. Hist. Mus._

It is not until we come to sands that are almost a quarter of a million

years old that we find any other particle of a sub- human being. But

there are plenty of implements, and they are steadily improving in

quality as we read on through the record. They are no longer clumsy

Eoliths; they are now shapely instruments made with considerable skill.

_And they are much bigger than the similar implements afterwards made

by true man._ Then, in a sandpit at Heidelberg, appears a single

quasi-human jaw-bone, a clumsy jaw-bone, absolutely chinless, far

heavier than a true human jaw-bone and narrower, so that it is

improbable the creature’s tongue could have moved about for articulate

speech. On the strength of this jaw-bone, scientific men suppose this

creature to have been a heavy, almost human monster, possibly with huge

limbs and hands, possibly with a thick felt of hair, and they call it

the Heidelberg Man.

A THEORETICAL RESTORATION OF THE PITHECANTHROPUS ERECTUS BY PROF. RUTOT

This jaw-bone is, I think, one of the most tormenting objects in the

world to our human curiosity. To see it is like looking through a

defective glass into the past and catching just one blurred and

tantalizing glimpse of this Thing, shambling through the bleak

wilderness, clambering to avoid the sabre- toothed tiger, watching the

woolly rhinoceros in the woods. Then before we can scrutinize the

monster, he vanishes. Yet the soil is littered abundantly with the

indestructible implements he chipped out for his uses.

THE HEIDELBERG MAN

The Heidelberg Man, as modelled under the supervision of Prof. Rutot

Still more fascinatingly enigmatical are the remains of a creature

found at Piltdown in Sussex in a deposit that may indicate an age

between a hundred and a hundred and fifty thousand years ago, though

some authorities would put these particular remains back in time to

before the Heidelberg jaw- bone. Here there are the remains of a thick

sub-human skull much larger than any existing ape’s, and a

chimpanzee-like jaw-bone which may or may not belong to it, and, in

addition, a bat-shaped piece of elephant bone evidently carefully

manufactured, through which a hole had apparently been bored. There is

also the thigh-bone of a deer with cuts upon it like a tally. That is

all.

THE PILTDOWN SKULL, AS RECONSTRUCTED FROM ORIGINAL FRAGMENT

_Nat. Hist. Mus._

What sort of beast was this creature which sat and bored holes in

bones?

Scientific men have named him Eoanthropus, the Dawn Man. He stands

apart from his kindred; a very different being either from the

Heidelberg creature or from any living ape. No other vestige like him

is known. But the gravels and deposits of from one hundred thousand

years onward are increasingly rich in implements of flint and similar

stone. And these implements are no longer rude “Eoliths.” The

archæologists are presently able to distinguish scrapers, borers,

knives, darts, throwing stones and hand axes ....

We are drawing very near to man. In our next section we shall have to

describe the strangest of all these precursors of humanity, the

Neanderthalers, the men who were almost, but not quite, true men.

But it may be well perhaps to state quite clearly here that no

scientific man supposes either of these creatures, the Heidelberg Man

or _Eoanthropus_, to be direct ancestors of the men of to-day. These

are, at the closest, related forms.

THE NEANDERTHALER AND THE RHODESIAN MAN

About fifty or sixty thousand years ago, before the climax of the

Fourth Glacial Age, there lived a creature on earth so like a man that

until a few years ago its remains were considered to be altogether

human. We have skulls and bones of it and a great accumulation of the

large implements it made and used. It made fires. It sheltered in caves

from the cold. It probably dressed skins roughly and wore them. It was

right-handed as men are.

Yet now the ethnologists tell us these creatures were not true men.

They were of a different species of the same genus. They had heavy

protruding jaws and great brow ridges above the eyes and very low

foreheads. Their thumbs were not opposable to the fingers as men’s

are; their necks were so poised that they could not turn back their

heads and look up to the sky. They probably slouched along, head down

and forward. Their chinless jaw-bones resemble the Heidelberg jaw-bone

and are markedly unlike human jaw-bones. And there were great

differences from the human pattern in their teeth. Their cheek teeth

were more complicated in structure than ours, more complicated and not

less so; they had not the long fangs of our cheek teeth; and also these

quasi-men had not the marked canines (dog teeth) of an ordinary human

being. The capacity of their skulls was quite human, but the brain was

bigger behind and lower in front than the human brain. Their

intellectual faculties were differently arranged. They were not

ancestral to the human line. Mentally and physically they were upon a

different line from the human line.

Skulls and bones of this extinct species of man were found at

Neanderthal among other places, and from that place these strange

proto-men have been christened Neanderthal Men, or Neanderthalers. They

must have endured in Europe for many hundreds or even thousands of

years.

THE NEANDERTHALER, ACCORDING TO PROF. RUTOT

In a few paragraphs a picture of the lush vegetation and swarming