306 ZOOLOGY 
on the ventral surface of each of the two seventeenth legs 
in the male; the enlarged crural gland of this segment opens 
at the apex of this. The genital organs are all included in 
the central division of the haemocoel. The unpaired external 
opening is ventral, and a little in front of the anus; on each 
side of it is a genital papilla, which represents the appendage 
of the twenty-first somite, and shows its homology with the 
legs by sometimes bearing claws. The male organs consist on 
each side of a testis, a prostate gland, and a vas deferens. 
The two vasa deferentia unite into a single duct which opens 
at the genital pore; at the same spot two glandular tubes, 
accessory glands, also open. The crural glands of the seven- 
teenth pair of legs are very much enlarged in the male, but 
their exact function is not known. The spermatozoa are 
filiform, and are united into bundles or spermatophores ; these 
are deposited by the male on any portion of the body of the 
female. It is unknown how the spermatozoa reach the ova, but 
they are always to be found in the cavity of the ovary. 
The ovary is unpaired, but is divided by a septum into two 
tubular halves; it is provided with two oviducts, which dilate 
into uteri. The ovary lies between the fifteenth and sixteenth 
pairs of legs; a receptaculum seminis is present, and cilia have 
been detected on its walls. The occurrence of cilia is remark- 
able, as they are not found elsewhere in the Arthropoda. 
Peripatus capensis is viviparous ; the fertilised eggs pass into the 
uteri in April, but are not hatched till the May of the follow- 
ing year; the period of gestation is thus thirteen months, and 
for the first month the ova of one generation, and the nearly 
mature embryos of the previous generation, co-exist in the uterus. 
The ducts of the generative glands are formed from the 
same portion of the twenty-first mesoblastic somite which 
gives rise to the nephridia in other segments; they may there- 
fore be regarded as modified nephridia, or, in other words, the 
generative ducts are nephrodinic. The generative glands 
themselves, the ovary and testes, are formed from parts of 
the true coelom of the sixteenth to the twentieth somite, 
and thus, as in so many other animals, the generative cells 
arise from the lining of the coelom, and pass to the exterior 
through modified nephridia. 
