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muscles of the feet and toes must have been acquired by 
ancestors, aS the result of taking to an arboreal life. Such 
flexibility would become more perfect in the adults by constant 
practice, and would be transmitted to their descendants earlier 
and earlier, so that those descendants would be able to reach 
still higher degrees of perfection. The same would be the case 
with the subsequent loss of the ability, owing to the abandon- 
ment of an arboreal life and consequent use of the hind limbs 
as mere supports on a flat surface. The young of such animals 
would still retain the old tree-climbing abilities and propen- 
sities; and only in later life would they, by constant practice, 
be able to assume something like the erect attitude. The 
ability to assume the erect attitude and to walk on the feet 
would be inherited earlier and earlier, and would in course of 
time appear as a character of the infantile stage—as in the 
human baby. 
It is the same with the loss of tail and the loss of hair. It 
is impossible to imagine that these characters arose as spon- 
taneous or abnormal variations in the infants of certain quad- 
rumana, and that these characters gave to these possessors 
such preponderating advantages that they ousted all their 
rivals in the struggle for existence. But if it be impossible to 
believe this, how is it possible to account for the disappearance 
of hair and loss of tail in the infant about the time of birth, 
except by the law of earlier inheritance ? 
A case analogous to the loss of body-hair is going on at 
the present day—namely baldness; and as this occurs during 
maturity—even in some cases while physical strength may be 
at its maximum—we may assume that the loss of body-hair 
occurred in the same way at the mature stage of life in our 
ancestors. Then it was transmitted by the law of earlier 
inheritance—gradually, at the same time, becoming no doubt a 
more perfect and extended process in the adults—until at the 
present day the human infant loses the greater portion of its 
hairy covering by the time it is three months old. The same 
arguments may be applied to the other characters which I have 
enumerated ; but I think these suffice to illustrate the evidence 
of earlier inheritance which Man affords. 
