VARIATION 209 



offspring are the famous Brown-Sequard experiments 

 with guinea pigs. From 1869 to 1891, Brown-Sequard 

 cut the sciatic nerve of the leg or the spinal cord in the 

 dorsal region, causing an abnormal nervous" condition 

 resembling the symptoms of epilepsy. These animals when 

 allowed to breed produced offspring, many of which were 

 epileptic like the parents. Similar results were later 

 secured by Westphal, Dupuy, Obersteiner and Romanes. 

 This interesting investigation has been promptly accepted 

 by the special advocates of the transmission of acquired 

 characters as fulfilling the oft repeated demand for direct 

 evidence of the inheritance of somatic modifications. 



In discussing the results it must not be forgotten that 

 the mutilation was never transmitted, but only the epilep- 

 tic state resulting from the mutilation. The results from 

 this type of mutilation were very diverse. According to 

 Romanes, the epileptic condition was rarely transmitted. 

 Brown-Sequard admitted that certain particular results 

 were exhibited in only one or two per cent of cases. If 

 this mutilation had actually influenced the germ-plasm 

 in such a way as to add to its fundamental constitution 

 the determiners essential for the development of the new 

 characters, then surely we might expect a larger part of 

 the offspring to be affected with the acquired character. 



Max Sommer in 1900 repeated the Brown-Sequard 

 experiments, but failed to confirm the conclusion that 

 this experiment had proven the existence of acquired 

 characters. " As regards the hereditary transmission of 

 epilepsy in guinea pigs," says Sommer, "or of other 

 accidentally acquired pathological symptoms e.g. de- 

 fects in the toes we have not been able to confirm 

 the experiments of Brown-Sequard and Obersteiner; 

 and we do not think that these can any longer serve as 



