I O PERIPATUS 



the luoiitli, and of working tliem alternately backwards or for- 

 wards. This is readily observed in individuals immersed in -water. 



Breeding. 



All species are viviparous. It has been lately stated that 

 one of the Australian species is normally oviparous, Ijut this has 

 not been proved. The Australasian species come nearest to laying 

 eggs, inasmuch as the e£fo-s are larse, full of v<-ilk, and enclosed 

 in a shell ; but development normally takes place in the uterus, 

 tliough, abnormally, incompletely de^'eloped eggs are extruded. 



The young of P. cajn-nsis are born in April and May. They 

 are almost colourless at liirth, excepting the antennae, which are 

 green, and their length is 10 to 15 nun. A large female will 

 produce thirty to forty young in one year. The period of gesta- 

 tion is thirteen months, that is to say, tlie o^-a 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 

 Ixmdles of spermatozoa cemented together Ijy some glutinous 

 substance, indiscriminately on any part of the Ijody of the female. 

 Such spermatophores are found on the ladies of both males and 

 females from July to January, but they appear to be most nume- 

 rous in our autunrn. 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 

 o^-ary. The testes are active from June to the following Jlarch. 

 From ]\Iarch 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 ^-entral surface (Fig. 6). 



^Vhereas in the Cape species embryos in tlie 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 



