3o6 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 cUia 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. 



