no Darwin, and after Darwin. 



ear, absence of toes, &c. In all these cases the facts, 

 as stated by Brown-Se"quard, are plainly unamenable 

 to any explanation which would suppose them due 

 to microbes, or even to any general neurotic con- 

 dition induced by the operation. They are much too 

 definite, peculiar, and localized. Doubtless it is on 

 this account that the school of Weismann has not 

 seriously attempted to deal with them, but merely 

 recommends their repetition by other physiologists *. 

 Certain criticisms, however, have been urged by 

 Weismann against the interpretation of Brown- 

 Sdquard's facts as evidence in favour of the trans- 

 mission of acquired characters. It does not appear 

 to me that these criticisms present much weight ; 

 but it is only fair that we should here briefly consider 

 them 2 . 



First, with regard to Brown- Se*quard's results other 

 than the production of transmitted epilepsy, Weismann 

 allows that the hypothesis of microbes can scarcely 

 apply. In order to meet these results, therefore, he 

 furnishes another suggestion viz. that where the 

 nervous system has sustained "a great shock," the 

 animals are very likely to bear " weak descendants, 

 and such as are readily affected by disease." Then, in 

 answer to the obvious consideration, " that this does 

 not explain why the offspring should suffer from the 

 same disease" as that which has been produced 

 in the parents, he adds ' But this does not appear 

 to have been by any means invariably the case. 



1 Essays, voL i. p. 82. 



* As Weismann gives an excellent abstract of all the alleged facts up 

 to date (Essays, voL i. pp. 319-324), it is needless for me to supply 

 another, further than that which I have already made from Brown- 

 Se\iuani. 



