4 Experimental Zoology 
Perhaps also the fact that the historical side of biology attracts 
such popular interest accounts, in part, for the neglect of more 
searching scientific methods of study. 
Whether the method of observation or the method of observa- 
tion and experiment is followed, seems to be also a question 
of the kind of interest aroused by living objects. If the number 
of collectors, naturalists, zodlogists, anatomists, entomologists, 
ornithologists, mammalogists, conchologists, etc., be compared 
with the number of physiologists, physiological chemists, bac- 
teriologists, it will be seen that the former have an enormous 
advantage in numbers. It is true that a few zodlogists are 
experimentalists, and that some physiologists do not experiment 
at all, but the proportion remains about the same. In other 
words, interest in collecting and recording the results of obser- 
vation and in the artistic side of nature is much more wide- 
spread than interest in the study of problems, or, if the interest 
is not lacking, the will to take the initiative in the formulation 
and solution of problems seems to be less cultivated in the 
biological sciences than the power to observe and to describe. 
In so far as the followers of the one or of the other method of 
investigation have made their selection as a matter of tempera- 
ment, the disproportion will probably always remain; but in so 
far as the result is due to imitation, or to following the line of 
least resistance, or to a failure to appreciate differences in aim 
and method, the proportion may to some extent be altered; and 
I think it will be generally admitted that at the present time there 
is greater need for experimental work than for descriptive and 
observational study. 
It is sometimes said that experimental study is the analytical 
study of problems, and this in a sense is true, but it is only a part 
of the truth. It is rather the method of attacking problems that 
is the chief characteristic of experimental work, for is not the 
historical method also a study of problems? We demand in 
the case of a problem in experimental science that the condi- 
tions under which an event takes place be discovered, and that, 
if possible, we reproduce artificially the result by controlling the 
