BRITISH WARBLERS 
many, then the attempt to explain the stereotyped uniformity, 
which we everywhere see around us, becomes even more 
difficult. Are we to suppose that the standard of intelligence 
has remained stationary, while by its assistance, instincts 
have been gradually built up or modified to suit changed 
conditions ? We cannot do so. For if such a faculty is 
really innate, it must have been, and must be still, subject to 
the same laws which have been responsible for the develop- 
ment in every other direction; it must therefore be more 
potent to-day than yesterday; it must, in fact, have deve- 
loped part passw with the selection of the more adaptive 
activities for which it has been responsible. I do not, of 
course, wish to imply an intellectual progress akin to that 
in human life, but a more highly elaborated perception and 
an increased capacity for taking advantage of opportunities 
as they arise, and the result of this would necessarily have 
been a corresponding increase in divergent individualism, 
and we ought in some measure to be conscious of the transi- 
tions and of the repeated attempts on the part of different 
individuals to depart from the normal type of activity. 
But this is not the case: the law of uniformity, in fact, 
precludes the possibility of it. We are therefore forced to 
conclude that if intelligence has really been operative, it 
has at the same time been unprogressive, while in every 
other direction progress has been made, and this I cannot 
believe. 
The importance of placing this question of individuality, 
with its far-reaching effects, beyond dispute cannot be over- 
estimated, since it directly affects the question as to whether 
animal species display any traces of intellectual development 
from generation to generation, and, indirectly, the possibility 
of a progressive development from animal to human intelli- 
gence, and consequently the whole subject of the genesis 
of mind. The final solution must rest with those naturalists 
who will devote themselves to the study of one, or at the 
most a few, species. 
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