i.l VARIATION AND HEREDITY 81 



by Brown-Sequard himself; 1 but a more plausible one 

 might be raised. Some experiments of Voisin and Peron 

 have shown that fits of epilepsy are followed by the elimi- 

 nation of a toxic body which, when injected into animals,' 

 is capable of producing convulsive symptoms. Perhaps 

 the trophic disorders following the nerve lesions made by 

 Brown-Sequard correspond to the formation of precisely 

 this convulsion-causing poison. If so, the toxin passed 

 from the guinea-pig to its spermatozoon or ovum, and 

 caused in the development of the embryo a general dis- 

 turbance, which, however, had no visible effects except 

 at one point or another of the organism when developed. 

 In that case, what occurred would have been somewhat 

 the same as in the experiments of Charrin, Delamare, 

 and Moussu, where guinea-pigs in gestation, whose liver 

 or kidney was injured, transmitted the lesion to their 

 progeny, simply because the injury to the mother's organ 

 had given rise to specific " cytotoxins " which acted on 

 the corresponding organ of the foetus.* It is true that, in 

 these experiments, as in a former observation of the same 

 physiologists,* it was the already formed foetus that was 

 influenced by the toxins. But other researches of Charrin 

 have resulted in showing that the same effect may be pro- 

 duced, by an analogous process, on the spermatozoa and 

 the ova.* To conclude, then: the inheritance of an ac- 



1 Brown-Sequard, "H6r6dit6 d'une affection due a une cause acci- 

 dentelle" (Arch, de physiologic, 1892, pp. 686 ff.). 



2 Voisin and Peron, "Recherches sur la toxicity urinaire chez lea 

 epileptiques" (Arch, de neurologie, vol. xxiv., 1892, and xxv., 1893. 

 Cf. the work of Voisin, L'fipilepsie, Paris, 1897, pp. 125-133). 



3 Charrin, Delamare and Moussu, "Transmission exp6rimentale aux 

 descendants de lesions d6veloppees chez les ascendants" (C. R. de I' Acad, 

 des sciences, vol. cxxxv., 1902, p. 191). Cf. Morgan, Evolution and 

 Adaptation, p. 257, and Delage, L'Heriditi, 2nd edition, p. 388. 



* Charrin and Delamare, "Heredite cellulaire" (C. R. de I' Acad, des 

 sciences, vol. cxxxiii., 1901, pp. 69-71). 



6 Charrin, "L'Her&iite' pathologique" (Revue generate des sciences, 

 15 Janvier 1896). 



