Spring is not the only rutting season. Love's calendar covers the year. In winter, wolves and foxes; in spring, the birds and fish; in summer, insects and many mammals; in autumn the deer. Winter is often the season chosen by polar animals; the sable couples in January; the ermine in March; the glutton, at the beginning and end of winter. Domestic animals have often several seasons; for the dog, cat and house-birds, spring and autumn. One finds young otters at any time. Most insects die after mating; but not all hemiptera, nor the queen bee, nor certain coleoptera, nor certain flies. The stag and the stallion empty themselves, but not the ram, nor the bull nor the he-goat. The duration of pregnancy in placentaires seems to have some relation to the size of the animal; mare, eleven to twelve months; ass, twelve months and a half; cow, doe, nine months; sheep, goat, wolf, vixen, five months; sow, four months; bitch, two months; cat, six weeks; rabbit, one month. There are oddities: fecundated in August, the roe is not delivered until seven and a half months later, the embryo remaining a long time stationary, and waiting for the spring to start again. In a she-bat ovulation does not take place until the end of winter, although she has received the male in the autumn: females caught during hibernation have the vagina swollen with inert sperm which does not act until the spring waking. [1] One has the unpronounceable name, savants designating it by the jumble of letters: Ptilinorhynches. The other is called the "gardener." [2] The title of his study is curious "Les Cabanes et les jardins de l'Amblyornis." (Annales du Musée d'histoire naturelle de Gênes, 1876). CHAPTER XVI POLYGAMY _Rarity of monogamy.--Taste for change in animals.-- Rôles of monogamy and polygamy in the stability or instability of specific types.--Strife of the couple against polygamy.--Couples among insects.--Among fish, batrachians, saurians.--Monogamy of pigeons, of nightingales.--Monogamy in carnivora, in rodents.-- Habits of the rabbit.--The ichneumon.--Unknown causes of polygamy.--Rarity and superabundance of males.--Polygamy in insects.--In fish.--In gallinaceæ, in web-footed birds.--In herbivora.--The antelopes harem.--Human polygamy.--How it tempers the couple among civilized races._