Atlanta tri-weekly journal. [volume] (Atlanta, Ga.) 1920-19??, 1922-10-10
ls. THE BEGINNINGS or RRAINs

|
All the innovations that come into the his
tory of life begin very humbly. The supply
Of blood vessels in the swimming bladder of
the mudfish in the lower Palaeozoic torrent
| river that enabled it to pull through a sea-
| son of drought, would have seemed at that
| time to that bod1less visitant to our planet we
have already imagined, very unimportant
side fact in that ancient world of great
sharks and plated fishes, sea scorpions and
| coral reefs and seaweed; but it opened the
| narrow way by which the land vertebrates
| arose to predom1nance. The mudfish would
have seemed then a poor refugee from the
too crowded and aggressive life of the sea.
But once lungs were launched into the world
| every line Of descent that had lungs went on
| improving them.
So, too, in the upper Palaeozoic the fact
! that some Of the Amphibia were losing their
! "amphibiousnessT by retardation of hatch
ing of their eggs would have appeared a
mere response to the distressfuI dangers that
| threatened the young tadpole Yet that pre-
| pared the conquest of the dry land for the
triumphant multitude of the Mesozoic rep
| tiles. 1t opened new direction toward a
| free and vigorous land-life along which all
the reptilian animals moved. And this
| viviparous, young-tending training that the
ancestral mammalia underwent during that
age Of inferiority and hardship for them, set
going in the world a new continuity of per-
ception, of which even man today only be-
| gins to appreciate the significance
Significant Little Things
| number of types of mammal already ap-
pear in the Eocene. Some are differentiating
| in one direction, and some in another some
are perfecting themselves as herbivorous
quadrupeds, some leap and climb among the
! trees, some turn back to the water to swim
but all types are unconsc1ously exploiting and
developing the brain which is the instrument
OF this new power of acquisition and edu-
cability.
In the Eocene rocks are found small early
predecessors of the horse (Eohfppus), tiny
| camels, pigs, early tapirs, early hedgehogs,
monkeys and lemurs, opossums and carniv-
ores. Now, all these were more or less an
cestral to living forms, and all have brains
relatively much smaller than their living
representatives There is, for instance, an
| early rhinoceros-like beast, Titanotherium,
with brain not one-tenth the size of that
of the existing rhinoceros The latter is by no
means q perfect type of the attentive and
submissive student, but even so it is 10 times
more observant and teachabIe than it's
predecessor.
This sort Of thing is true of all the orders
and families that survive until today All the
Cainozoic mammals were doing this one
thing in common under the urgency of a
common necessity; they were all growing
brain. 1t was a parallel advance. In the
same order Of family today, the brain is us.
ually from to 10 times what it was in the
Eocene, ancestor.
The Eocene period displayed series of
herbivorous brutes of which no representa-
tive survives today. Such were the Uinta-
there's and the Titanotheres. They were
| ousted by more specialized graminivorous
forms as grass spread over the world.
In pursuit Of such beasts came great
| swarms of primitive dogs, some as big as
bears, and the first cats, one in particular
(Smilodon), a small fierce-looking creature
with big knife-like CANNES, the first saber-
| toothed tiger, which was to develop into
greater things. American deposits in the
Miocene display great variety of camels