‘Observation sets the problem; experiment solves it, 
always presuming that it can be solved, or at least if 
powerless to yield the full light of truth, it sheds a cer- 
tain gleam over the edges of the impenetrable cloud.’’ 
—J. H. FABRE, 
“So the first task of comparative psychology is to find 
out the instinctive equipment of any animal studied. In- 
stincts are, however, well worth study for their own sake. 
An instinctive fear of a certain enemy may be as truly 
useful to an animal as sharp teeth or protective colora- 
tion. Instincts are the expression of structures and func- 
tions of the nervous system, and are as real and as im- 
portant matters for the biologist as are bones and blood 
vessels.’’ 
—E, L, THORNDIKE. 
‘It may be noted that all the activities of ants, their 
reflexes and instincts as well as their plastic behavior, 
gain in precision with repetition. In other words, all 
their activities may be secondarily mechanized to form 
habits, in the restricted sense of the word. This is tanta- 
mount to say that even the reflexes and instincts are not 
So stereotyped but that they may become more so by ex- 
ercise during the lifetime of the individual. And not only 
do ants thus form habits, but . . . these habits when 
once formed are often hard to break. It is certain that 
many instincts . . . are at first complete and indefi- 
nite and are guided to their proper course by stimuli 
that affects the organism at a later period. .... There 
is little doubt, moreover, that the more fixed or stereo- 
typed instincts are phylogenetically the older.’’ 
—wmM. M. WHEELER. 
