106 Proceedings of Boy al Society of Edinburgh. [sess 
“ heredity.” That there is similar material to start with is one 
half of the truth ; that there are similar conditions throughout the 
development is the other. 
VII. Inheritance of Acquired Characters. 
The third problem, which we stated at the outset, concerned the 
inheritance of acquired characters. It is well known that many 
organisms in the course of their individual life are affected by 
environmental influences, or by use and disuse of their organs. 
Environmental and functional variations of the body of the indi- 
vidual organism thus result. The question is, whether these may 
he transmitted to the offspring by the parent which acquires them. 
Two cautions may be noted in starting — (1) No naturalist doubts 
the inheritance of constitutional or organismal variations. These 
may he reasonably traced hack to the fertilised egg-cell. But what 
is involved in the fertilised egg-cell is also, by hypothesis, involved 
in the germ-cells which give rise to the next generation. There is 
no argument on this fact ; the present scepticism relates to func^ 
tional and environmental variations. (2) No one doubts that 
functional and environmental variations often reappear. Many 
doubt, however, that they reappear because they have been trans- 
mitted. Another alternative is obviously open. The conditions 
which originally brought about a given change may still persist, 
and may hammer the same effect upon the offspring which they 
wrought upon the parent. 
Doubt as to the transmission of acquired characters is not novel. 
It has, however, become precise in Weismann’s statement. Brock 
has noticed that even the editor, whoever he was, of Aristotle’s 
Historia Animalium seems to have differed from his master on this 
subject. Aristotle naively refers to the inheritance of the exact 
shape of a certain cautery ; but the editor seems to doubt whether 
apparent instances of the inheritance of acquired characters are not, 
after all, exceptional. The same writer notes Kant’s vigorous 
opinion against the transmission of such individual features, and 
also Blumenbach’s cautious inclination to the same position. In 
more recent times, His expressed his strong conviction against such 
inheritance ; and Galton is at once cautious and emphatic. Pfliiger 
is also among the earlier sceptics. A few sentences from Galton, 
