heredity, that the cure in the parent which has so characteristic stages should have exactly the same stages in the young as to circumstances and time?
I have said that I would only deal with this subject of heredity in its physiological aspects, but I cannot refrain from recalling to the attention of the reader that such facts in the human species need to be studied by psychological physicians, because they occur in insane patients, as is well known. Those alterations of the ears of which I have spoken at first are frequently met with in the ears of demented patients; physicians call them bæmatoma. I have satisfied myself that it is even more frequent than suspected in the inmates of asylums. That state of stupor, or stupidity, and of insanity, in the Guinea-pig, is of very frequent occurrence in the human epileptic. I could tell a long story of similar phenomena observed in our own species.
I believe that, if any conclusion can at present be drawn from those facts, a physiologist or a physician will state that it is not a disease which is inherited, which is transmitted, but the power to develop such a disease. On the one hand, a physiologist is bound to accept that the disease was originally developed as a consequence of an anatomical alteration of a certain organ or nerve-cell or fibre; and on the other he is bound to consider that the same disease or consequence develops itself in a young one which has no such circumstances of anatomical alteration of a certain organ or nerve-cell or fibre—at least detectable by any means of investigation at present employed.
This question of heredity is one of the most vexed, and I shall not say much more about it at present; but as I have stated that I am sure that there were no causes of error in the facts themselves or the deductions drawn from them, I take this opportunity to say that Mr. Galton has committed a grave error, in his very remarkable paper on "Heredity" published not very long ago, in which he stated that the Guinea-pigs which had epilepsy without alteration induced in their nervous system may have acquired the disease by imitation, just as, it is well known, is too frequently the case in the human species.
First, all the children or adults who happen to live with epileptic patients and witness their paroxysms do not develop epilepsy; only a very few do so. This fact would show, therefore, that those who do develop epilepsy have some tendency; but the argument of Mr. Galton does not hold good with regard to the first two series of facts which I have reported, and specially in the case of the Guinea-pigs which inherit epilepsy. How will he account, on the strength of his hypothesis, for the fact that, out of a couple of hundreds of young which were born from epileptic parents during the lapse of several winters in Dr. Brown-Séquard's laboratory in Paris, and which I have very studiously watched, only three became epileptic, although all lived together and all witnessed the fits of their parents, and only those three
