quired and transmitted peculiarities, beyond
the famous experiments of Brown-Sequard, repeated and confirmed by other
physiologists.[41] 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.[42] This objection
has been answered by Brown-Sequard himself;[43] 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,[44] 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 disturbance, 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.[45] It is true that, in these experiments, as in a former
observation of the same physiologists,[46] 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 produced,
by an analogous process, on the spermatozoa and the ova.[47] To
conclude, then: the inheritance of an acquired peculiarity in the
experiments of Brown-Sequard can be explained by the effect of a