138 The Journal 
fall behind in the mental race, for they 
are not sufficiently stimulated. 
“The second great crisis was the 
change which caused certain forms of 
life to become warm-blooded. This not 
only enabled man’s animal ancestors to 
continue their vital activities at all sea- 
sons and in almost all parts of the 
world, but it gave rise to the close bond 
between mother and child which has 
been the greatest of all factors in pro- 
moting the higher qualities of love and 
altruism. 
“The third great crisis was the sep- 
aration of man—the two-handed, two- 
footed, big-brained creature—from his 
four-handed and smaller-brained rela- 
tives. This was the time when mental 
qualities evolved most rapidly. There- 
fore it interests us most of all because 
the conditions which fostered the evo- 
lution of our minds are those which 
today stimulate them most strongly. 
“Tt is perhaps a misnomer to speak of 
these as crises, for each of these three 
steps in evolution required a long time 
for its consummation. Yet as we look 
backward into the dim vistas of the 
past, the steps are so foreshortened that 
they appear like genuine crises. They 
are, as it were, great slopes in a ter- 
raced plain. For long periods the life 
of the world was confined to the waters. 
Then during a relatively brief period, as 
geology counts time, there came a trans- 
formation. The highest forms that in- 
habited those ancient seas—that is, 
the fishes—gave rise to a stock which 
left the water and made its home on 
land. Then our ancestors, for such 
they were, moved on once more across 
the vast plain, rising here and there 
over smaller terraces, until at last they 
began to climb to the warm-blooded 
condition. Another vast stretch of 
plain and minor terraces brought them 
to the final steep upward slope. At its 
base our ancestors were animals; at its 
top they were men. 
MORE- PROGRESS TO COME 
“But have we yet reached the top? 
More likely we are now upon the very 
steepest part of the terrace. Hitherto 
of Heredity 
we have climbed upward because some 
unknown force kept driving us. Now 
we are conscious of ourselves, and are 
able to direct our movements. It is 
for us to say whether we will climb 
straight upward, or whether, like many 
of the creatures of the past, we will 
wander this way and that, and perhaps 
fail to be among the chosen few who 
finally emerge at tthe highest level.” 
It was the aridity of the air during 
the Devonian period which caused the 
development of amphibians with legs 
and lungs, Dr. Huntington surmises; 
while a second long drought in the 
Mississippian period, millions of years 
later, caused all those to perish except 
the ones that could lay their eggs on 
land and did not have to return to the 
water. Thus the reptiles were estab- 
lished and the first crisis, the ‘transi- 
tion from water to land, had been 
weathered. 
“Not till millions of years later did 
the next great step in evolution occur. 
That step was the rise of the warm- 
blooded mammals. We do not find 
their fossil record until the time known 
as the Upper Triassic, but they must 
have originated farther back, appar- 
ently in the Permian. The date of the 
Permian Period is estimated as any- 
where from 10,000,000 to 200,000,000 
yearsago. The break between the types 
of life before and after this great crisis 
is the most profound anywhere in the 
history of evolution. It is therefore 
highly important to find that this was 
also the time of the greatest changes of 
climate. Vast glaciers descended to 
sea level within 30° of the equator. 
Perhaps at no other time during the 
evolution of man’s ancestors has there 
been such a succession of cold, stormy, 
glacial epochs alternating sharply with 
mild, interglacial epochs. 
“Let us consider the effect of such 
climatic stress upon other forms of life 
as well as upon our ancestors. Previous 
to the Permian Period the vegetation 
of all parts of the earth’s surface, in- 
cluding even the far north, was much 
alike. In general the lands were cov- 
ered with forests, averaging perhaps 
