i VARIATION AND HEREDITY 85 



single unquestionable example of acquired and trans 

 mitted peculiarities, beyond the famous experiments 

 of Brown-Sequard, repeated and confirmed by other 

 physiologists. 1 By cutting the spinal cord or the 

 sciatic nerve of guinea-pigs, Brown-Sequard brought 

 about an epileptic state which was transmitted to the 

 descendants. Lesions of the same sciatic nerve, of the 

 restiform body, etc., provoked various troubles in the 

 guinea-pig which its progeny inherited sometimes in a 

 quite different form : exophthalmia, loss of toes, etc. 

 But it is not demonstrated that in these different cases of 

 hereditary transmission there had been a real influence of 

 the soma of the animal on its germ-plasm. Weismann 

 at once objected that the operations of Brown-Sequard 

 might have introduced certain special microbes into the 

 body of the guinea-pig, which had found their means 

 of nutrition in the nervous tissues and transmitted 

 the malady by penetrating into the sexual elements. 2 

 This objection has been answered by Brown-Sequard 

 himself; 3 but a more plausible one might be raised. 

 Some experiments of Voisin and Peron have shown 

 that fits of epilepsy are followed by the elimination 

 of a toxic body which, when injected into animals, 4 is 

 capable of producing convulsive symptoms. Perhaps 

 the trophic disorders following the nerve lesions 

 made by Brown-Sequard correspond to the formation 



1 Brown-S&juard, &quot; Nouvelles Recherches sur 1 epilepsie due a certaines 

 lesions de la moelle epiniere et des nerfs rachidiens &quot; (Arch, de physiologie, vol. 

 ii., 1866, pp. 211, 422, and 497). 



2 Weismann, Aufsatze iiber Vererbung, Jena, 1892, pp. 376-378, and also 

 Vortrage iiber Descendenzt/ieorie, Jena, 1902, vol. ii. p. 76. 



3 Brown-Squard, &quot;Here&quot;dite&quot; d une affection due a une cause acci- 

 dentelle&quot; (Arch, de p/iysiologie, 1892, pp. 686 ff.). 



4 Voisin and Peron, &quot; Recherches sur la toxicite urinaire chez les 

 e pileptiques &quot; (Arch, de neurologic, vol. xxiv., 1892, and xxv., 1893. 

 Cf. the work of Voisin, L pilt:psie, Paris, 1897, pp. 125-133). 



