The Inheritance of Acquired Characters 63 



They are collected from all parts of the system to constitute 

 the sexual elements, and their development in the next genera- 

 tion forms a new being. . . ." 



A few experiments have been made to test this view. Galton * 

 transfused the blood of one variety of rabbit into the veins of 

 both sexes of another species, and then bred together the latter. 

 If there are gemmules in the blood, the germ-cells of the rabbits 

 containing the transfused blood might possibly show the influ- 

 ence of the other variety. No evidence of such an influence 

 was found. 



Darwin did not admit that this experiment was decisive, and 

 Galton himself admitted that the results are not convincing. 

 Darwin thought that the few gemmules present in the blood 

 at any one time might not succeed in supplanting the similar 

 kinds of gemmules supposed to be already present in the germ- 

 cells. 



Another experiment was carried out by Romanes. Wild 

 rabbits supplied the blood, and Himalayan rabbits received it. 

 Several transfusions were made. In one case the blood of 

 three wild rabbits passed through the veins of the domesticated 

 individual. No evidence of any "foreign" influence was found 

 in the offspring. Romanes said later that he had discovered 

 that this experiment could not have been expected to give any 

 positive results, because rabbits when crossed do not produce 

 young having intermediate character. The force of the admis- 

 sion is not very convincing, however, for the offspring might 

 still have been expected to show the effects if such influences 

 are transmitted in this way of the dominant breed, if this had 

 been used to supply the transfused blood. Moreover, Castle 

 has shown that in some breeds of rabbits certain characters at 

 least are intermediate in the hybrid the length of the ears, for 

 example. 



Other zoologists who have refused to accept the doctrine of 

 the inheritance of acquired characters Weismann, for instance 

 have nevertheless used another idea contained in Darwin's 



1 Proc. Roy. Soc., 1871. 



