22 
of genealogical relationship, are incomplete, 
are in many respects still hypothetical and 
often misleading ; that our methods of study 
have not been sufficiently exact; that a 
little judicious clipping of the wings of our 
scientific imagination will render its flight 
safer, even though it may not soar so high. 
But let us not depreciate the importance of 
the comparative study of normal phenomena 
to which biology already owes so many 
brilliant triumphs, and which, as we may 
confidently hope, has still so many future 
achievements in store. The true aim of the 
naturalist is to understand the conditions 
of living forms as they now exist and have 
existed in the past; but what are these 
conditions if not the result of an illimitable 
series of experiments, carried on by nature 
since life began? Under what other inter- 
pretation has the theory of natural selection 
any meaning? Comparative morphology 
and physiology but record and coordinate 
the results of these experiments. The ex- 
periments performed in our laboratories but 
supplement those that have taken place and 
are always taking place in nature, and their 
results must be wrought into the same 
fabric. 
One final thought, and I have done. I 
have said that the key-note of Agassiz’s 
life and work was his love of nature; and 
in this respect I believe he was typical of 
the great naturalists of every age. It has 
of late become the fashion in some quarters 
to look with a certain condescension on 
what is styled the ‘sentimental side’ of 
natural history, on that keen primary in- 
terest in biological phenomena for their own 
sake, apart from their scientific analysis, 
that was characteristic of so many of the 
earlier naturalists. I can but believe that 
such an attitude shows a lack of insight into 
the real motives and sources of inspiration 
of all great observers and discoverers. 
Every critical analysis of the progress of 
science leads to a recognition of the vital 
SCLENCE. 
[N.S. Von, XIII. No. 314. 
importance of the imaginative faculty in 
all research of a high order; and in this 
regard great masters of creative science, 
such as Faraday or Darwin, have rightly 
been placed beside the great masters of 
creative art. But this faculty is nearly 
akin to the esthetic sense. Karl Pearson, 
in his admirable ‘Grammar of Science’ re- 
marks, ‘‘ Both works of art and laws of 
science are the product of the creative 
imagination, both afford material for the 
esthetic judgment.’’ Pearson is here re- 
ferring, it is true, to the sense of beauty and 
harmony aroused by the discovery and con- 
templation of natural law. Beyond this, 
however, we must recognize that there is no 
more potent spring of scientific research 
than a lively interest in the facts—in other 
words, the esthetic satisfaction that lies in 
the mere observation of natural phenomena. 
Read the intimate records of the lives of 
great discoverers in every field of science, 
and you cannot fail to be struck with this. 
From this source flows the impulse to ana- 
lyze by experiment, to correlate by com- 
parison and thus to discover law. The 
primary impulse of the naturalist is thus 
given by the love of nature ; and I believe 
that the scientific naturalist should welcome 
every movement toward the cultivation of 
general interest in natural history. We 
may therefore regard it as a happy omen for 
the future of our science that in every di- 
rection we see the signs of increasing inter- 
est in field work, in nature-study and in the 
teaching of natural history in our schools. 
Tt would be an evil day for the more ad- 
vanced and precise study of biology when it 
came to be regarded as actuated by motives 
having nothing in common with the love of 
nature that inspired such men as Darwin, 
Agassiz, Audubon and Gray; but we need 
not fear that such a day will come. For 
my part, I believe that the newer experi- 
mental study is better calculated to foster 
an interest in nature than much of the 
