856 Recent Literature. [ August, 
evolution question, as may 
from a letter of his to the Spectator (London) of Jan. 11, 1873: 
“ Sır:—Any one interested in the subject to which you atuo 
at p. 42 of your last number, namely, the relative importance in 
causing modifications of the body or mind, on the one hand of 
habit or of the direct action of external conditions, and on | 
other hand of natural or artificial selection, will find this subject 
briefly discussed in the second volume (pp. 301-315) of my ‘Va- 
riation of Animals and Plants under Domestication.’ 
* * 
which cannot be thus accounted for. He would be a bold man 
who would attempt to explain by these means the origin of the 
exsertile claws and great canine teeth of the tiger; i 
horny lamellæ on the beak of the duck, which are so we pted 
for sifting water. Nor would any one, I presume, even att 
to explain the development, for instance, of the beautifully plumed 
seeds of the dandelion, or of the endless contrivances 
necessary for the fertilization of very many flowers by ii 
through gradually acquired and inherited habit, or through 
direct action of the external conditions of life. pea 
> twos 
„Now, it is precisely what Mr. Darwin here declares 
difficult that the causal evolutionists, as distinguished ret is, 
selective evelutionists, set themselves to accomplish. capable of 
which are 7 
firstly, to show that in the case of animals and plants incapa! w 4 
movements of their own, their structure has been modine? ce of 
scent by the influences of their environment, while px? ar = 
in 7 
those beings that can move, modification is the com 
of the mutual interaction of the organism and its environ! paces 1 
together. Since the general result displays adaptation, the 
school must ultimately discover whether it be intelligen 
is thus displayed or not, and if so, whence it proceeds. oolo- 
_ The botanists are here in a greater dilemma than the 20° 
gists, but the extraordinary discoveries of the relations of ise 
to plants, bid fair to extricate them from their difficulty. | 
