It cannot be disputed, also, that the development of the mental faculties lessens very materially the sexual impulse, that impulse being always strongest in races of the lowest order of intelligence; and among animals also, as Mr. Darwin has shown, the most stupid are always found to be the most sexual and lascivious. Either as a cause or result of this, stands the equally noticeable fact that, as we descend in the scale of intelligence, both with man and animals, the larger and more abnormally developed do the genitals of the male become; the negro, long distinguished for the size of his penis and testicles, being, through this circumstance, placed side by side with his analogues of the brute creation in which a like development is observable, namely, the ass, stallion and boar.1
Idiots, also, exhibit the same rule as to size of genitalia and grossness of sexuality.* How much the actual refinement of the mental processes, however, has to do with lessening sexual activity, and how much control a higher degree of culture may exercise upon the human passions in general, are questions not yet scientifically settled. There is one thing certain, however, the greater difficulty which a higher degree of social refinement necessarily creates in the selection of a suitable and compatible life-mate, must tend to at least delay the marriage period. There are considerations, also, of a serious or religious character, involved in the contract among a thinking people which the less enlightened fail to regard, but which will obviously influence to some extent the question under discussion.