According to observers and breeders, it is the female who is specially susceptible of sentimental selection. The male, even the male of birds, is more ardent than the female, that is to say, more intoxicated and more sharply pricked by instinct, and thus generally accepts any female whatever: all are alike to him. This is the rule, but it is not without exceptions; thus, the male pheasant shows a singular aversion to certain hens. Amongst the long-tailed ducks some females have evidently a particular charm for the males, and are courted more than the others.[21] The pigeon of the dovecot shows a strong aversion to the species modified by breeders, which he regards as deteriorated.[22] Stallions are often capricious. It was necessary, for example, to use stratagem in order to induce the famous stallion Monarch to beget Gladiateur, who became still more famous.[23] Analogous facts have been observed in regard to bulls.[24] But it is more especially the females who introduce individual fancy into sexual love. They are subject to singular and inexplicable aversions. Mares sometimes resist, and it is necessary to deceive them.[25] Female pigeons occasionally show a strong dislike to certain males without apparent cause, and refuse to yield to their caresses. At other times a female pigeon, suddenly forgetting the constancy of her species, abandons her old mate or legitimate spouse to fall violently in love with another male. In the same way peahens sometimes show a lively attachment to a particular peacock.[26] High-bred bitches, led astray by passion, trample under foot their dignity, honour, and all care for nobility of blood, to yield themselves to pug-dogs of low breed or mongrel males. We are told of some who have persisted for entire weeks in these degrading passions, repulsing between times the most distinguished of their own race.[27] Even among species noted for their fidelity it sometimes happens that acts of sexual looseness are committed. The female pigeon often abandons her mate if the latter is wounded or becomes weak.[28] Misfortune is not attractive, and love does not always inspire heroism. In concluding this short study of sexual union in the animal kingdom, I will attempt to formulate the general propositions which may be drawn from it. All organic species undergo the tyranny of the procreative function, which is a guarantee of the duration of the type. The phenomenon of reproduction, when detached from all the complicated accessories which often conceal it in bi-sexual species, goes back essentially to the conjugation of two cellules. With intelligent animals the procreative function echoes in the nervous centres under the form of violent desires, which intensify all the psychic and physical faculties in awakening what we call love.