22 ESSAYS SCIENTIFIC AND PHILOSOPHICAL. 



self-fertilized, and when Sir John Lubbock assures 

 us that " nature sets her face against self-fertiliza- 

 tion " we can see why it is so. For cross-fertiliza- 

 tion has a similar advantage over self-fertilization, 

 that sexual reproduction has over reproduction by 

 fission. It multiplies the materials on which 

 natural selection can operate. And to multiply 

 the possible variations in plant or animal is to 

 multiply the chances of survival in the struggle for 

 existence. 



Whatever modifications Professor Weismann's 

 theory may receive, it will, at all events, have 

 stated a new problem, a problem of the deepest 

 scientific interest, and pointed the way to its 

 solution. If we may not call it a new departure, 

 it is at least a new development in the theory of 

 evolution. 



NOTE. 



A doctrine of Heredity which involves the non- 

 transmission of acquired characters, if it ever be 

 proved or generally accepted, can hardly fail to 

 have a bearing upon questions of morals and 

 society and even theology itself. No doubt those 

 who see in evolution a ready weapon for use 

 against the belief in creation will catch at Professor 

 Weismann's theory as a new argument against the 

 doctrine of original sin. For the present it is 



