I20 Darwin, and after Darwin 



I myself lost two years of work on account of not 

 knowing this exact spot before going to Paris for the 

 purpose of seeing Brown-S^quard himself perform 

 the operation. I had in the preceding year seen one 

 of his assistants do so, but this gentleman had a much 

 more careless method, and one which in my hands 

 yielded uniformly negative results. The exact spot 

 in question in the restiform body is as far forwards as 

 it is possible to reach, and as far down in depth as is 

 compatible with not producing rotatory movements. 



7th. Absence of two toes out of the three of the hind leg, and 

 sometimes of the three, in animals whose parents had eaten up 

 their hind-leg toes which had become anaesthetic from a section 

 of the sciatic nerve alone, or of that nerve and also of the crural. 

 Sometimes, instead of complete absence of the toes, only a part 

 of one or two or three was missing in the young, although in the 

 parent not only the toes but the whole foot were absent. 



As I found that the results here described were 

 usually given by division of the sciatic nerve alone — 

 or, more correctly, by excision of a considerable por- 

 tion of the nerve, in order to prevent regeneration — 

 I did not also divide the crural. But, although I have 

 bred numerous litters from parents thus injured, there 

 has been no case of any inherited deficiency of toes. 

 My experiments in this connexion were carried on 

 through a series of six successive generations, so as to 

 produce, if possible, a cumulative effect. Nevertheless, 

 no effect of any kind was produced. On the other 

 hand, Brown-S^quard informed me that he had 

 observed this inherited absence of toes only in about 

 one or two per cent, of cases. Hence it is pos- 

 sible enough, that my experiments have not been 

 sufficiently numerous to furnish a case. It may be 



