230 TJ^ANSMISSIOX OF ACQUIRED CHARACTERS 



§ II. Brown- S equar d' s Experiments on Guinea-Pigs 



In recent discussions of modification-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. 



