04: PRINCIPLES OP STOCK-BREEDING. 



grows gradually. The fits become simple convulsions, 

 then mere twitchings, and lastly the animal can no 

 longer be distinguished from another healthy one, but 

 by the fact that it has only one toe at one of its hind- 

 legs, when the operation has been performed on the 

 sciatic nerve; and nothing whatever remains when 

 the origin of the disease was a prick in the spinal 

 cord." 1 



The young of these epileptic Guinea-pigs are born 

 apparently healthy, with the exception of those from 

 parents that had been subjected to the injury of the 

 sciatic nerve, and they have but one toe on one of the 

 hind-feet. When these apparently healthy animals 

 are two or more months old they gradually become 

 affected with epilepsy, and the same area on the face 

 and neck passes through the same series of changes in 

 the development and cure of the affection that had 

 been observed in their parents. " We see the gradual 

 increase of the affection, the diminution of the sensi- 

 bility in the zone, just as with the parents, the coming 

 of a period of complete attacks of epilepsy, and then 

 the loss of hair and the gradual diminution of the 

 nervous complaint." 2 



In the original parents, it will be observed that the 

 derangement of the nervous system, resulting in con- 

 vulsions, was produced by an injury to the spinal cord 

 or the sciatic nerve, and, when these injuries had 

 healed, the nervous symptoms gradually disappeared, 

 the hair is shed from that part of the face affected, and 

 gradually replaced, and the cure is complete. 



1 Popular Science Monthly, July, 1877, p. 337. 

 9 Loc. cit., p. 337. 



