572 Mr. Graham Brown. Alleged Specific Instance of [Dec. 9, 



(five in number) were brown rats stated to be bred from a white tame 

 mother and a brown wild father. 



It was found that degenerative changes in the foot were far rarer in the 

 rats than in the guinea-pigs from which a piece of the great sciatic nerve had 

 been removed. 



A " complete " phenomenon, similar to that seen in guinea-pigs, was not 

 obtained. But it was found that the ordinary scratch-reflex — analogous to 

 the " incomplete " phenomenon — was raised in excitability upon the side of 

 the lesion. If the inside of the ear, or the skin behind the ear, was 

 tickled, it was found that upon the side of the lesion the scratch-reflex 

 was evoked, but this did not occur upon the other side. 



These rats produced many litters of young. An exact register was not 

 kept, but the number of young was greater than 120. Many of these (about 

 40 to 50, or more) were carefully examined, but a raised excitability to the 

 scratch-reflex was in no instance seen. That is to say, that scratching was 

 not obtained in response to a stimulus of equal value to that which produced, 

 upon the side of the lesion, scratching in the parents. 



VI. Conclusions Concerning the Alleged Transmission of the Brown- SSquard 

 Phenomenon. 



If the preceding conclusions regarding the nature and causation of the 

 phenomenon be accepted, they throw some light upon the question of 

 the value of the experiments of Brown-Sequard as an example of the trans- 

 mission of an acquired character, for the state itself cannot be regarded as 

 an acquirement. The mechanism is present in every guinea-pig, and the 

 possibility that it be rendered apparent in the phenomenon is always there. 

 The peculiarity of the condition in the parent is that a certain specific 

 mechanism in the central nervous system is rendered more excitable than 

 usual. Thus the question of transmission in this case is not " is a 

 mechanism which arises de novo in the parent transmitted to the offspring ? " 

 but " does a state of the raised excitability of a reflex mechanism already 

 present in the parent condition by inheritance a similar raised excitability 

 in the offspring ? " 



Before considering the answer to this question notice may briefly be taken 

 of Galton's suggestion (27) that the appearance of the phenomenon in the 

 offspring is due to imitation of the parent. This is, to say the least, 

 extremely unlikely. In no case was such imitation seen in these 

 experiments. 



In support of the affirmative answer to the question the experiments 

 of Brown-Sequard and of others may be quoted. If the negative be 



