Page:Popular Science Monthly Volume 19.djvu/683

Rh Several more or less closely analogous cases have been recorded; but until within a recent period every one naturally felt much doubt whether the effects of a mutilation or injury were ever really inherited, as accidental coincidences would almost certainly occasionally occur. The subject, however, now wears a totally different aspect, since Dr. Brown-Séquard's famous experiments proving that Guinea-pigs of the next generation were affected by operations on certain nerves. Dr. Eugène Dupuy, of San Francisco, California, has likewise found, as he informs me, that with these animals "lesions of nerve-trunks are almost invariably transmitted." For instance, "the effects of sections of the cervical sympathetic on the eyes are reproduced in the young, also epilepsy (as described by my eminent friend and master Dr. Brown-Séquard) when induced by lesions of the sciatic nerve." Dr. Dupuy has communicated to me a still more remarkable case of the transmitted effects on the brain from an injury to a nerve; but I do not feel at liberty to give this case, as Dr. Dupuy intends to pursue his researches, and will, as I hope, publish the results.—Nature.



HE problem of races in the United States is one of growing interest and of great practical moment; that of the colored race, especially at the present time, is full of significance in its social and political aspects. It is proposed in a couple of articles to inquire briefly into the phenomena of increase and movement of the colored population in the light of the most recent observations and statistics which bear upon the subject. The first table we shall consult is that which gives the increase of the white and of the colored population for each decade from 1790 to 1880:

