There have been differing opinions among physicians in reference to the effects upon offspring, both physical and mental, of consanguineous marriages. Several French physicians have written able articles, the tendency of which is to indicate that such marriages result in deaf-mutism and idiocy. It has been claimed that the statistics of asylums for the deaf and dumb, the blind, and the idiotic, give color to such conclusions. Among those who have more or less fully and carefully examined the subject, with results tending to confirm such a theory may be mentioned Dr. Bemis, of Kentucky; Dr. Chazarain, of Bordeaux; and Mr. Boudin. On the other hand, there have been adduced numerous statistics which indicate that no unfavorable results follow such marriages, which can fairly be considered as arising from consanguinity. Without entering fully into the details of this discussion, I propose simply to indicate certain principles and facts which have been pretty definitely settled, and such inferences as may appear to be entirely legitimate, and also have a bearing on our subject. For a more exhaustive examination of the question, I may refer the reader to Ribot, on "Heredity," and Miles, on "Stock-Breeding." 1. The ancient Egyptians, the Persians, the Syrians, and some other nations, were accustomed to practise consanguineous marriages. Brothers married sisters, cousins married cousins in all degrees of relationship, and sometimes even fathers cohabited with their own daughters. Dr. McGraw[15] says "there can be no doubt that close and continual interbreeding has taken place time and again, without evident injurious consequences, among simple and uncultivated communities. Notable examples are the Pitcairn Island settlements, formed from the close in-and-in-breeding of the progeny of four mutineers from the ship _Bounty_, and nine native women; the small community of fishermen, near Brighton, England; the numerous small and isolated villages of Iceland; and the Basque and Bas-Breton settlements among the Pyrenees. We must admit, from overwhelming evidence, that under such circumstances as the settlements just mentioned afforded, consanguinity among married people does not necessarily cause evil results to the progeny. If it be asked how it would be with men of more civilized habits, we are unfortunately obliged to confess that there are no statistics whatever on the subject which can give us any exact and trustworthy information." 2. Experiments in interbreeding of cattle go to prove that in some cases, at least, this may be continued for many generations with no unfavorable results. A friend of mine has bred in-and-in a herd of Jersey cattle, as close as a father to his progeny, for five generations, and with apparently good results. I have a flock of India pigeons which have been in-bred for fifteen years to my own knowledge, and apparently with no deterioration. They are still strong, vigorous, and prolific.