2io TRANSMISSION OF ACQUIRED CHARACTERS 



ii. Brown-Sequard's Experiments on Guinea-Pigs 



In recent discussions of mo dificat ion-inheritance much pro- 

 minence has been given to the experiments made by Brown- 

 Sequard, Westphal, and others on the apparent transmission of 

 artificially induced epilepsy in guinea-pigs. The reason for this 

 prominence is that the case is not without cogency, and that 

 a record of precise experiments (although of a somewhat ugly 

 character) comes as a relief amid anecdotal evidence. Prof. 

 E. Ray Lankester goes the length of saying (1890, p. 375), " The 

 one fact which the Lamarckians can produce in their favour is 

 the account of experiments by Brown-Sequard, in which he pro- 

 duced epilepsy in guinea-pigs by section of the large nerves or 

 spinal cord, and in the course of which he was led to believe that 

 in a few rare instances the artificially produced epilepsy was 

 transmitted." As the case has been often discussed e.g. by 

 Romanes (1895, vol. ii. chap, iv.) we shall treat of it briefly. 



What the Experiments were. Through a long series of 

 years (1869-91), Dr. Brown-Sequard, a skilful and ingenious, 

 if somewhat impetuous, physiologist, experimented on many 

 thousands of guinea-pigs. He made a partial section of the 

 spinal cord in the dorsal region, or cut the great sciatic nerve of 

 the leg ; he observed that the injury was followed after some 

 weeks by a peculiar morbid state of the nervous system, cor- 

 responding in some of its features to epilepsy in man ; he allowed 

 these morbid animals to breed, and found that the offspring were 

 frequently decrepit, and that a certain number had a tendency 

 to the so-called epilepsy. 



Results of the Experiments. If it be understood that we have 

 omitted or altered a few difficult technicalities, we may call the 

 following statement Brown-Sequard's summary of his results. The 

 inverted commas are ours : 



(i) "Epileptic" symptoms appeared in the offspring of parents 

 who had been rendered " epileptic " by an injury to the 

 spinal cord. 



