1880] Working v. Fighting . 77 1 
merit ? Not, assuredly, their own good pleasure. The pole- 
mics have been due to the “ parsons, poets, artists, lawyers,” 
metaphysicians, and the like, who, as such , and without the 
biological discipline needful for understanding the evidences 
of the question, have come forward to dogmatise on the for- 
mation and the correlations of species and have even laid 
the flattering undtion to their souls that they, forsooth, were 
better able to appreciate fadts than the men whose special 
task is observation and discovery. 
These Babel-voices, literary, aesthetic, teleological, are now 
fading into a wholesome quiet, and Evolution is about to 
undergo its veritable trial— the scrutiny whether it can be 
fairly made to harmonise with and to account for the many 
puzzling phenomena which we recognise on every hand — 
whether the hypotheses which have been set up can be 
verified by exadt research. If unable to stand this test they 
will be laid aside by naturalists without any bidding from 
the lay public. . . 
The two works just mentioned, proceeding from authorities 
whose competence is beyond question, are valuable contribu- 
tions to this great task, and though approaching the subjedt 
independently and from different sides, they are substantially 
in accord with each other. Prof. Semper— after a thoughtful 
and suggestive introdudtory sedtion, of which anon - 
considers in detail the influence upon animal life of the 
environment in which it is placed, i.e. f nutiiment, light, 
temperature, standing water, still air, flowing water, and 
living organisms. All these agencies may adt upon animal 
species by transformation, by seledtion, and by dispersion, 
and their effedts have as yet been but very slightly and 
imperfedtly studied. Lamarck, indeed, as is well known, 
ascribed the development of plants and animals as we now 
find them to such causes as abundance, scarcity, or peculiar 
quality of food, excess or deficiency of moisture, and the 
like. But his views, however important, remained mere 
speculations, not verified by observation and experiment,— 
an undertaking which in his day would certainly have been 
found impradticable. “ The task of the zoologist, therefoie, 
says Prof. Semper, “ is to examine how vital conditions adt 
upon individual animals and their organs, in order to infer 
back to the physiological causes of the origin of different 
animal forms.” It will be noted that he does not overlook 
the transforming or modifying agency of outward circum- 
stances. Most naturalists now fully admit that natural 
seledtion,” or, indeed, seledtion of any kind, though it may 
preserve and increase advantageous modifications when once 
