PT. n. Mr. Darwin and Mr. Buckle. t 77 



adaptation of the male and female organs to each 

 other. Now how, in the first instance, could this 

 division into the two sexes have been effected by 

 Natural Selection ? Did it occur in the parent stock, 

 and was it handed down through the successive varie- 

 ties, or was Natural Selection to effect it again in 

 each particular case ? Supposing that the first was 

 a single being, how was the division into the two 

 sexes effected ? Could Natural Selection do this ? 

 for in order that the male and female should be 

 fitted for their respective parts, a very elaborate 

 adaptation of their bodily organs would become 

 necessary ; but they must be furnished with these at 

 once in order to fulfil the purposes for which they 

 were made, and nature could not afford to stand still 

 for several generations while Natural Selection was 

 perfecting them, even if it could possibly perfect 

 them at all. 



The instinct which by the process of sexual con- 

 nection sets in motion the whole machinery by which 

 Life in its different forms is renewed and perpetuated 

 is among the strongest in the economy of nature. 

 How it could spring from Natural Selection alone is 

 beyond my comprehension ; but it is also to be noted 

 that it is not only implanted in the vast majority of 



