THE PRESIDENTIAL ADDRESS 21 
not more than a quarter of an ounce to control each ton of body and 
limb ; and we begin to understand why they lost the lordship of 
creation. 
The proportion of brain to body improved in those reptiles which 
took to flying, possibly in relation to their acquisition of warm blood, 
and in the birds evolved from reptiles ; but it is only in mammals 
that a marked advance is seen. Here the brain of Uintatherium, 
a great rhinoceros-like animal of Eocene date, weighing 2 tons, 
was about the size of that ofa dog. This proportion of half a pound 
of brain to each ton of body shows how far the mammals had gone, 
and still had to go. 
A 12-stone man of the present day has about 34 pounds of brain— 
an amount not far short of half a hundredweight per ton. 
Even though we can know nothing of its material, this steadfast 
growth in the guiding principle, through the millions of centuries 
that have gone to its development, is surely one of the most remark- 
able conclusions that we owe to geology. Of all the wonders of the 
universe of which we have present knowledge, from the electron to 
the atom, from the virus and bacillus to the oak and the elephant, 
from the tiniest meteor to the most magnificent nebula, surely there 
is nothing to surpass the brain of man. An instrument capable of 
controlling every thought and action of the human body, the most 
intricate and efficient piece of mechanism ever devised ; of piercing 
the secrets and defining the laws of nature ; of recording and recalling 
every adventure of the individual from his cradle to his grave; of 
inspiring or of ruling great masses of mankind ; of producing all the 
gems of speech and song, of poetry and art, that adorn the world, 
all the thoughts of philosophy and all the triumphs of imagination 
and insight : it is indeed the greatest marvel of all. 
And when we contemplate the time and energy, the sacrifice and 
devotion, that this evolution has cost, we must feel that we are still 
far from the end of this mighty purpose: that we can confidently 
look forward to the further advance which alone could justify the 
design and skill lavished on this great task throughout the golden 
ages that have gone. 
