Page:George Archdall Reid 1896 The present evolution of man.djvu/142

130 spermatheca? And if the tissues in general, why not the tissues on the surface of the ovary in particular? At any rate this is clear, that while there is not a particle of evidence to show that the female acquires and transmits traits from a previous sire, there is some evidence to show that her germ cells do.

We have now reviewed the whole of Mr. Spencer's articles so far as they deal with "The Inadequacy of Natural Selection," and taking the counter-arguments into consideration, I think he can hardly be said to have established his case. But in a foot-note (p. 33) he mentions a series of experiments which at first sight certainly prove, or seem to prove, that acquired traits may sometimes be transmitted. Brown-Sequard severed the sciatic nerve in some guinea-pigs; epilepsy thereupon supervened, and was apparently inherited by the offspring subsequently born, for they also were epileptic. Weismann's attempted explanation that certain hypothetical microbes entering the wound caused epilepsy in the parent, and infecting the unborn offspring, produced epilepsy after birth in them as well, appears to me improbable and far-fetched. However, Mr. Spencer himself does not attach very much importance to Brown-Sequard's experiments. He says of them in the pamphlet we have under consideration—"Let me say I do not commit myself to any derived conclusions;" and in a previous publication he says—

"Considerable weight attaches to a fact which Brown-Sequard discovered quite by accident in the course of his researches. He found that certain artificially-produced lesions of the nervous system, so small even as a section of the sciatic nerve, left after healing an increased excitability which ended in liability to epilepsy; and there afterwards came out the unlooked-for result that the offspring of guinea-pigs which thus