She-brown bears and she-kangaroos are smaller than males. In all the deer tribes save reindeer the male alone is horned, and this is the by no means ridiculous origin of a very old joke, for the does are lascivious and are pleased to receive the attentions of a number of males. The difference of bull and cow is distinct enough, that of stallion and mare less so, diminishing still further between dog and bitch, and being almost null among cats. In all cases where the dimorphism is slight, and is the direct consequence of the possession of sexual organs, castration inclines the male toward the female type.[3] This is as apparent in cattle as in eunuchs or gelded horses. One may see in this yet another proof of the primitivity of the female, since the abstraction of testicles suffices to give the male that softness of form and character which typifies females. Masculinity is an augmentation, an aggravation of the normal type represented by femininity; it is a progress, and in this sense it is a development. But this reasoning, good for mammals, would be detestable among insects, where the accentuation of type is nearly always furnished by the female. There are no general laws in nature, unless they be those which regulate all matter. With the birth of life, the unique tendency diverges at once upon multiple lines. Perhaps we must throw this point of divergence still further back, for a metal like radium seems to differ from other metals as much as an hymenopter from a gasteropod. [1] Bird, rather like quail. [2] Translator's note. O sinistre continent. [3] Castration of females seems, at least, among humans, to bring them nearer the male type. Effects of castration vary, necessarily, according to the age of the subject. CHAPTER VI SEXUAL DIMORPHISM _III. Vertebrates (continued).--Man and woman.--Characteristics and limits of human dimorphism.--Effects of civilization.--Psychologic dimorphism.--The insect world and the human.--Modern dimorphism, basis of the pair.--Solidarity of the human pair.--Dimorphism and polygamy.--The pair favours the female.--Sexual æsthetics.--Causes of the superiority of feminine beauty._