20 THE PRESIDENTIAL ADDRESS 
The answer of the grass-feeders, with their specialised hoofs, 
teeth and bones, better suited to flight than fight, was to seek safety 
in numbers, and thus develop the herd instinct, with its necessity 
for leadership and discipline ; but this, in turn, provoked a like 
rejoinder from some types of their enemies. 
When it is remembered how much of the meat and drink and life 
of mankind is bound up with the grasses, including wheat, maize, 
millet and other grains, sugar-cane, rice and bamboo, we must 
realise how close is his link with the development just outlined. 
Practically his whole food supply is provided by them, either directly 
by the agriculturist who grows little else but grasses, or indirectly 
by the herdsman whose domestic animals are fed chiefly on the same 
food. Nor must we forget that almost every one of our domesticated 
animals has been derived from the gregarious types just mentioned, 
which have accepted the leadership of man in place of that of their 
own species. 
It is perhaps not too much to say that the magnificent outburst of 
energy put out by the earth in the erection of the Alps, Andes, and 
Himalayas in Tertiary times was trivial in its influence for man’s 
advent and his successful occupation of the earth in comparison with 
the gentle but insidious growth of ‘ mere unconquerable grass ’ and 
its green carpet of “ wise turf ’ which in some form clothes by far the 
greater part of the land of the globe. 
The kind of developmental reaction of which this is but a single 
example must clearly have had influence on bodily features other 
than bones and horns, teeth and claws, speed and strength ; and one 
of the most striking has been on intellectual development and the 
size and shape of brain. 
We do not, and perhaps can never, know the quality of the material 
of which the brains of fossil creatures was made, for we have no 
instrument to pierce the veil of time as the spectroscope has pene- 
trated the abysm of space. But we are even now learning something 
about their shapes and convolutions, and more about their mass in 
its relation to the size of the bodies controlled; from the time of 
the earliest Ordovician fishes, through the history of the amphibia, 
reptiles, birds, and mammals, up to man himself. 
The brain of those gigantic if somewhat grotesque reptiles the 
dinosaurs, the tyrants of Mesozoic time, is relatively tiny. In 
Diplodocus, 80 feet in length and 20 tons in weight, the brain was 
about the size of a large hen’s egg. It is true that there was a big 
supplementary sacral ganglion which may have taken chief charge 
of locomotion and helped to secure co-ordination throughout the 
hinder part of its huge length and bulk ; but of true brain there was 
