[2] This does not seem to be general. I have recently observed, on the umbels of wild carrots, numerous couples of scutilaries, proceeding by cavalage, the male inert, couched on the walking female, who started at the least alarm. Form narrow, almost cylindrical; colour: orange red, with two short black bands: strong sucker, long antennæ. Union lasting at least a day and a night.--R. de G. CHAPTER XI THE MECHANISM OF LOVE _III. Of birds and fish.--Males without penis.--Coupling by simple contact.--Salacity of birds.--Copulation of batrachians: accoucheur toad, aquatic toad, earth toad, pipa toad.--Fœtal parasitism.--Chastity of fish.--Sexes separated in love.--Onanistic fecundation.--Cephalopodes, the spermatophore._ _III. Of birds and fish_. It is toward the middle of the second month that the separation of the cloaca into two regions is marked in the human foetus: a partition is formed which will absolutely isolate the digestive channel from the uro-genital. The persistence of the cloaca is not a sign of primitivity, since one finds it in selacians, batrachians, reptiles, monotremes and birds. The uro-genital region of marsupials and of several rodents is submitted to a single sphincter, witness of original union. The bird's cloaca is divided into three chambers, for the three functions, the outer orifice being necessarily unique, by definition. It is with this rudimentary apparatus that most birds turn to the pleasures of love. The male being wholly deprived of any erectile tissue, coition is by simple contact, a pressure, perhaps a rubbing; displeasing as the comparison may be, it is a play analogous to the mouth to mouth kiss, or, if one prefer, to the pressing of two sapphists clasped vulva to vulva. Far from being a regression or a stop, it is perhaps a progress, the male at least gaining in security and vigour, being obliged to very little muscular development. The salacity of certain birds is well known, and one does not see that the absence of an exterior penis diminishes their ardour, or attenuates the pleasure which they find in these succinct contacts. Perhaps the direct genital pleasure is concentrated in a vascular papilla which swells a little at the moment of the approaches; this is very rudimentary, often unnoticeable but it seems to be an exciting organ, the producer of pleasure. The male mounts the female, holds her with feet and beak, the two cloaca are superposed, the sperm flows into the oviduct. One sees sparrows repeat the sexual act as often as twenty times, always with the same excitement, the same expression of contentment; the female tires first, and shows her impatience. Birds' habits are especially interesting in reason of the play with which they surround their love making, their parades, their combats; we will deal with this in later chapters.