Consideration of Weismann’s Arguments 179 
4. Finally the last argument of Weismann is that 
it is incomprehensible how the inheritance of acquired 
characters could be effected.1!2 
In the endeavor to examine these four arguments 
with the most scrupulous objectivity, we must first divide 
them into two categories: The fourth is the only one 
which attacks the principle of inheritance directly; the 
first, the second, and the third, on the contrary, con- 
trovert this theory only indirectly, in that they seek to 
show that many formations are of such a nature or 
arose under such circumstances that they can be explained 
only by the theory of natural selection. The conclusion 
which it is desired to have drawn from this is clear, and 
is indeed admitted: If natural selection is capable of 
explaining some formations it will be capable also of 
explaining all the others; if all formations can be ex- 
plained by natural selection alone, the inheritance of 
acquired characters becomes useless for the purpose of 
explaining the transformation of species; consequently 
if it is useless it is very probable that it does not exist 
at all. 
The impartial reader will admit that this manner of 
reasoning is deceptive. Even if it be proved that natural 
selection must necessarily have been capable of producing 
certain formations with the help of fortuitous individual 
variations, it does not follow that it must also have been 
capable of producing all other phylogenetic formations, 
especially if they are different in nature from the former. 
And even if the proof were forthcoming that it is capable 
of explaining by itself all phylogenetic formations what- 
ever, it is evident that even this would not constitute 
142Weismann: Ibid. P. 61. 
