28 ANIMAL INTELLIGENCE 
incumbrance. Let me, then, briefly indicate some of 
the problems that have seemed to myself and others as 
most urgently demanding solution. 
One of the questions still far from clear is that which 
we had under discussion last year, viz.: In how far can 
the lower animals understand man’s various forms of 
expression, especially his spoken words? A priori, we 
should not expect that creatures unable to invent words 
should have the capacity to understand them in the 
sense in which man himself does. I am inclined to 
think that more has been claimed for the inferior races 
of animals in this direction than an exact examination 
of the subject will warrant. On the other hand, we 
have probably very much underrated their capacity to 
comprehend our various forms of unspoken longuage. 
The subject calls for close observation. A kindred 
problem is the degree to which various kinds of animals 
can communicate with one another. This is a much 
more difficult subject, and it may prove that the 
creatures we despise as so very much inferior may 
have modes of subtle communication which we are, 
possibly, incapable even of comprehending. 
The whole subject of the senses of the lower animals 
is a field for investigation both by the psychologist and 
the physiologist; all the more important, as it is’ 
scarcely possible to understand one form or degree of 
sensation adequately, except by comparison with its 
lower and higher forms. The field is as yet but little 
tilled, but enough has been done to suggest this very 
important question: Do the senses of the lower animals 
and those of man differ only in degree, or also in kind ? 
Is the sense of smell, eg. in the dog, merely more 
acute, or is it not also characteristically different? The 
latter seems the more probable, when we consider how 
different the hearing of man is in some respects (music) 
from that of other animals, even the dog. 
a 
