114 ANIMAL INTELLIGENCE 
must be equally clear to those who, guided by facts 
alone, untrammelled by tradition and dogma of every 
kind, compare the pyschic status of the young with 
that of the mature animal, that psychogenesis is a fact ; 
that the mind does unfold, evolve, develop equally with 
the body. And as with the body so with the mind, 
each stage in this development can only be under- 
stood in the light of all the previous stages. 
This truth is apparently as yet only dimly compre- 
hended, for, till recently, studies on psychic history, 
development or psychogenesis have been all but un- 
known, and as yet, even in the case of man, are very 
few and confessedly imperfect. 
But just as we have an ontogeny and phylogeny, 
just as the anatomy, physiology, and pathology of 
man are clearer from comparative studies on creatures 
lower in the scale, so must it be in regard to man’s 
psychology. 
It follows, then, that all researches in comparative 
psychology must be as welcome for the general science 
of mind, and the special study of human psychology, 
as those in comparative anatomy are to anatomy in 
general, or the anatomy of man in particular. 
Till very recently animals below man seem to have 
been almost wholly neglected or misunderstood in all 
that pertains to their psychic nature, one very obvious 
result of which has been the inability to connect the 
psychic states of man with others of similar, yet often 
simpler, character in lower animals, not to mention 
the impossibility of a science of mind in general, or 
a true understanding of the psychic side of man’s 
nature. Studies in infant psychology are of compara- 
tively recent date, few in number, and in most instances 
very incomplete; while, as regards animals lower in 
the scale, such investigations are still more imperfect. 
The relations of mind and body in both health and 
