BROWN-S&QUARUS EXPERIMENTS 233 



It is stated that the morbid condition of the parents was also in- 

 duced by bruising the sciatic nerve without cutting the skin, or by 

 striking the animals on the head with a hammer. If this be so it 

 seems to show that the result may occur without any associated 

 microbe influence, and possible infection of the offspring thereby 

 (Weismann's criticism, in part). The hypothesis of microbes does 

 not seem to be supported by any definite facts, but we note that it 

 is not entirely excluded by Ziegler in his review of possible ex- 

 planations (1886, p. 29). 



Brown-Sequard experimented with both males and females, and 

 although he got more striking results with the latter, he did not fail 

 with the former. This seems to lessen the force of the criticism that 

 the offspring were affected during gestation, and therefore not, in 

 the strict sense, hereditarily. 



Criticisms. (i) The original modification was cutting, bruising, 

 or destroying part of the nervous system ; the subsequent result was 

 the " epileptic " state, and the various other diseased conditions 

 mentioned. It need hardly be said that the mutilation or injury 

 inflicted on the parent was never reproduced in the offspring, though 

 the subsequent results sometimes were. 



(2) The conditions exhibited by the offspring were very diverse 

 general feebleness, motor paralysis of the limbs, trophic paralysis 

 resulting in loss of toes, cornea, etc., other nervous and sensory dis- 

 orders, and in some cases the particular " epileptic " state. In a 

 number of cases the condition of the offspring was so different from 

 that of the parent, that the only common feature was that in both 

 cases there were abnormal neuroses. Romanes, while regarding his 

 results as corroborations of those of Brown-Sequard, admitted that 

 the epileptic condition was only rarely transmitted. 



(3) Even numerically there was no small diversity in the results. 

 Thus in one set of experiments (Obersteiner, 1875), out of thirty-two 

 young ones born of " epileptic " parents, only two showed symptoms 

 of " epilepsy " and paralysis, three were paralytic, and eleven were 

 only weak. Romanes did not find that any of the offspring of parents 

 who had eaten their toes off showed, even in six generations, any 

 defect in these parts. Even Brown-Sequard only observed this 

 peculiar " transmission " in about i or 2 per cent, of cases. 



(4) Prof. Ziegler 's criticism is partly based on the allegation 

 that guinea-pigs (as we keep them in captivity) are pathological and 

 nervous animals, very readily thrown into an epileptic state. On 



