All species are viviparous. It has been lately stated that one of the Australian species is normally oviparous, but this has not been proved. The Australasian species come nearest to laying eggs, inasmuch as the eggs are large, full of yolk, and enclosed in a shell; but development normally takes place in the uterus, though, abnormally, incompletely developed eggs are extruded. The young of _P. capensis_ are born in April and May. They are almost colourless at birth, excepting the antennae, which are green, and their length is 10 to 15 mm. A large female will produce thirty to forty young in one year. The period of gestation is thirteen months, that is to say, the ova pass into the oviducts about one month before the young of the preceding year are born. They are born one by one, and it takes some time for a female to get rid of her whole stock of embryos; in fact, the embryos in any given female differ slightly in age, those next the oviduct being a little older (a few hours) than those next the vagina. The mother does not appear to pay any special attention to her young, which wander away and get their own food. There does not appear to be any true copulation. The male deposits small, white, oval spermatophores, which consist of small bundles of spermatozoa cemented together by some glutinous substance, indiscriminately on any part of the body of the female. Such spermatophores are found on the bodies of both males and females from July to January, but they appear to be most numerous in our autumn. It seems probable that the spermatozoa make their way from the adherent spermatophore through the body wall into the body, and so by traversing the tissues reach the ovary. The testes are active from June to the following March. From March to June the vesiculae of the male are empty. There are no other sexual differences except in some of the South African species, in which the last or penultimate leg of the male bears a small white papilla on its ventral surface (Fig. 6). Whereas in the Cape species embryos in the same uterus are all practically of the same age (except in the month of April, when two broods overlap in _P. capensis_), and birth takes place at a fixed season; in the Neotropical species the uterus, which is {11}always pregnant, contains embryos of different ages, and births probably take place all the year round. In all species of _Peripatus_ the young are fully formed at birth, and differ from the adults only in size and colour. ANATOMY THE ALIMENTARY CANAL (Fig. 8).