378 



PJROF. AV. J. DAKIN ON THE 



of tlie gland-duct wJiich opens to tlie exterior provided with 

 a swollen circular lip which forms the crural papilla. The 

 surrounding epidermis is retractile and may be iuvaginated 

 to form a little Crural Pit. The crural papilla is then quite 

 invisible from the exterior, but this is merely a temporary con- 

 dition, and consequently there is no point in counting visible 

 crural papillje m these animals unless the count is checked by 

 sections. With the exception of the last pair of gla.nds, opening 

 on the last pair of appendages, tlie aperture of the gland leads to 

 a narrow duct bounded by small cubical cells. This duct runs 

 upwards to open into a large vesicle which extends distally and 

 occupies quite a large extent of the leg-cavity. The vesicle itself, 

 i. e., the crural gland proper (see PI. IV. fig. 10) is lined by a 

 layer of small and compact cubical epithelial cells with large nuclei 

 centrally placed. The glands are usually I'eadily distinguished 

 by reason of the contents, which in sections stained with hfema- 

 toxylin and eosin appear bright pink. Still more characteristic 

 is the fact that the contents are perfectly homogeneous and 

 noii-grcijudar. 



The first pair of Crural Glands differs considerably from all the 

 rest. The duct opens in the same manner as in the succeeding 

 glands but instead of leading to a sac in the leg it passes into the 

 lateral cavity of the body and opens into an elongated sac which 

 runs almost the entire length of the animal (see PI. I. fig. 3, 

 Cr.Gl.'). This tubular gland can be easily picked out in transverse 

 sections, for it is always cut transversely and lies not far from 

 ^he lateral nerve-cord and below the salivary gland in sections 

 where this is also present. The structure of its wall is quite 

 characteristic. 



These extraordinaiy crural glands of tlie first legs were dis- 

 covered in the West Australian Peripatoides from the hills near 

 Perth by Bouvier. They are noted in his monograph as peculiar 

 to the species. It is important, therefore, to note that the same 

 feature is present in the southern variety — in short, this character 

 is peculiar to both West Australian varieties of Peripatoides. 



The Crural Glands of the ptemdtimate legs are extremely 

 minute. The duct is short and leads into a, very small vesicle. 

 Bouvier was uncertain as to whether crural glands existed here 

 at all. He was unable to find them in his specimens. 



The Crural Glands of the last pair of legs are very difi;erent 

 from all the others. The ducts pass direct from the legs into the 

 central body-cavity, where they lead into two somewhat wide 

 tubes which run forwards entangled in the coils of the gonoducts 

 (see PI. I. fig. 3, Cr.Gl."). 



Crural glands and crural papillae are features of the male sex, 

 but in Willey's account of the Anatomy and Development of 

 Pe7'ipatus 7iovce-hritannice (13) the following reference occurs 

 to crural glands in the female: "Wherever they occur (crural 

 glands) tliey are found onl}'^ in the male except in P. capensis. 

 where they arp said to occur in the female also (Sheldon). 



