1891.] Are Acquired Variations Inherited ? 193 
The emphasis here is upon the contrast between our knowledge 
of the fact of variation (op. cit. p. 373) and our indefinite knowledge 
. of the causes of variation.’ In other words, we have been accumu- 
lating facts, and our present induction from them is that the varia- 
tions which have formed the main basis of evolution are fortuitous ; 
there may be, indeed, definite causes, but the effects are largely 
indefinite. Now if all, or even the great majority, of naturalists 
were in agreement with Lankester, we might claim to have madea 
distinct advance since 1870, even in having reached such a negative 
conclusion—that is, on the principle that we progress when we 
recognize that no further progress is possible. 
But fortunately, or otherwise, this is not the case, for in oppo- 
sition to those who share Lankester’s opinions are an equally large 
number who would balance the account differently, and claim 
that the distinctive feature of the past twenty years of study is that 
we have reached some of the fundamental principles of variation 
which Huxley presented as the goal of research. 
* But this difference in the accounts does not stop here. We 
biologists are obliged to frankly confess to our fellow-scientists in 
chemistry and physics, and tothe world generally, that after studying 
Evolution for a century we are in a perfect chaos of ae as to ” 
factors. Thereisactually no to the pow 
selection principle, none as to the laws of ER none as to the 
influences of environment! In the very heart ofthis disturbance is 
the problem we have come together to discuss. It is the medium 
Sy Ee, ona one Ce + thefact f i 
LU UE 
We may continue to accumulate facts, but no actual advance can be 
made in the study of natural causation until this problem is abso- 
lutely settled one way or the other. This being the case, Weismann 
has done a monumental service in forcing this question to an issue. 
It is true a very large number of naturalists consider the question no 
longer sub judice ; but as half this number hold one opinion, and the < 
other half an opinion directly opposed, we are forced to the criti- 
cism that neither side can at present offer such a clear and full 
z of the views of all authors 
tere quoted, and arm aware that a single passage fin misleading., On he present 
subject compare other recent essays and reviews of Prof. Lankester, principally those in 
Nature, 
