40 EVOLUTION 
to it. Now, theories of heredity apart, and leaving 
aside the results of minute observations which had 
not been made in Lamarck’s time, the natural supposi- 
tion undoubtedly is that acquired characters are 
inherited just as much as any others. Given the ob- 
served fact that offspring resemble their parents more 
closely than they do other members of the same species, 
it is natural to believe that the child will take after 
the forms exhibited by its parents at the time of its 
conception rather than after those shown by them at 
any previous period of their lives. This seems to be 
the natural view in the absence of any other evidence 
for or against, and so accurate a thinker as Herbert 
Spencer, writing before the publication of the * Origin 
of Species,’ regarded the term inheritance as neces- 
sarily implying inheritance of this particular kind. 
For this reason it has sometimes been thought that 
Darwin scarcely accorded to Lamarck the appreciation 
which he deserved ; and yet Darwin himself fell back 
upon the Lamarckian explanation on the few occasions 
when natural selection seemed to have failed him. 
When, however, we come to know more of the actual 
facts of sexual generation, we find that it is very 
difficult, if not impossible, to imagine any kind of 
mechanism by which this supposed transmission of 
acquired modifications can take place. We shall defer 
the further discussion of this subject, as well as the 
question of the existence of direct and other evidence 
of use inheritance, until the latter half of the next 
chapter, where we shall refer briefly to the contro- 
