260 Tt Fel CORTS EE: focToBER 
both how separate parts as well as correlative parts are modified. 
Present-day knowledge goes to show that such changes are brought 
about through the co-operative influence of the correlative brain 
centres. Yet, strange it is that the leader of the Neo-Lamarckians, 
Mr. Herbert Spencer, while he cannot see how natural selection can 
produce such changes as are shown in the neck, etc., of the elk, has to 
fall back on natural selection to explain the modifications shown in 
the fore-quarters of the giraffe, a more difficult matter than the elk’s 
neck to bring under the influence of natural selection. If the changes 
in the elk’s neck cannot be explained by natural selection, how can 
the parts of the giraffe, a more marked form of correlative function 
change, be so explained? If natural selection is to be ruled out as 
regards the elk’s neck, it must more surely be ruled out as regards the 
girafte. 
I have already stated that Weismann, like a true Lamarckian, 
attributes variations to the influences of the environment on the germ- 
plasm during the ontogenetic development of the body. That being 
eranted, we can readily perceive how change of habit can produce in 
time change of characters through inheritance of the functional modi- 
fications brought about through the change of habit. It is well known 
that many animals have, not one source of food supply, but several. 
A bird that visits a flower for honey may also be insectivorous. One 
source of food supply failing, the habit of constantly satisfying hunger 
from another is taken on; and this, by change in the method of feeding, 
leads to the increase of use of certain characters which co-operatively 
are brought into action, and the disuse of certain other characters. In 
this way distribution of animals or change of conditions im sitw leads 
to new habits. But does the new habit modify the species in the 
direction of better adaptation to the new mode of life? I would 
answer that if the experiences of the mother influence the foetus, and 
act as external stimuli on the germinal cells, as is allowed by Weis- 
mann, we must see that changes in that experience, as brought about 
by a new habit, must be reflected on the foetus, producing a variation 
in the direction of better adaptation. And this process of better 
adaptation in each successive offspring must, in time, render the 
species fully adapted to its new mode of life. We find here not only 
the cause of variation, but the gradual process by which species 
through a change of habit becomes adapted to their new lite. As the 
functional changes affect characters, new species are produced. Now, 
assuming that the Neo-Darwinians admit this modus operandi of the 
formation of new habits, our explanation of the inheritance of func- 
tional modifications of characters would harmonise the two schools, 
i.e. if we allow that Weismann represents the Neo-Darwinians. 
Let us now consider how functional changes, as brought about 
by a change of habit, modify anatomically the characters affected. 
It must be plain that all modifications of form must have been 
