CHINESE EARTHWORMS GATES 493 



The spermathecal duct is stoutish, usually slightly shorter than 

 the ampulla from which it is more or less clearly demarcated. Near 

 the parietes the duct is swollen and has a more or less strongly 

 marked, bulbous appearance. Removal of the longitudinal mus- 

 culature discloses in the parietes a rather thick, firm column. This 

 column is usually removed Avhen the spermathecal duct is pulled 

 out from the parietes, the spermathecal pore tubercle on the ventral 

 face of the column. When the spermathecal duct is pulled out from 

 the parietes of softened specimens the column is not removed, but a 

 very slender, conical portion of the spermathecal duct is pulled out 

 from the center of the column. At the end of the conical portion 

 of the duct is the spermathecal pore surrounded by the tiny whitish 

 ring of tissue previously mentioned. In this case a circular hole with 

 a smooth margin is left in the spermathecal pore tubercle. The 

 diverticulum passes into the median face of the duct close to the 

 parietes and comprises a smooth, glistening stalk with a narrow 

 lumen and a thin- walled seminal chamber with a wider lumen. The 

 seminal chamber is usually looped back and forth in a regularly 

 zigzag fashion; the limbs of the loops are short and in apposition 

 but may be straight or nearly so, twisted variously or loosely and 

 irregularly looped. The diverticulum (in the looped condition) is 

 about as long as or longer than the combined lengths of duct and 

 ampulla. The length of the diverticular stalk varies considerably. 



In the parietes just behind each spermathecal duct there is usually 

 visible a mass of glandular tissue slightly protuberant into the coe- 

 lomic cavity and forming a sort of U-shaped half -collar on the poste- 

 rior face of the ectal end of the spermathecal duct. Some of the 

 stalks or ducts from this glandular mass may be firmly attached to 

 the duct but do not appear to pass into the duct. In xviii, on the 

 parietes, anterior or median or posterior to the ectal end of the pro- 

 static duct there is usually visible glandular tissue in one or more 

 discrete masses with ducts passing to the genital markings in the 

 male pore invagination. The glandular masses are usually flattened 

 and not conspicuously protuberant into the coelomic cavity. 



Rernarhs. — A number of the specimens, including the largest worm 

 (330 by 13 mm) and the types of P. tibetana^ are heavily parasitized. 

 Some of these parasitized worms are obviously abnormal. Possibly 

 the abnormalities have developed as a result of the parasitic infection. 

 Among the abnormalities noted are the following : Rudimentary sper- 

 mathecae, spermathecal duct unusually long (much longer than the 

 ampulla), seminal chamber very loosely looped or with but one or 

 two loops or practically straight. Possibly the absence of genital 

 markings in some of the parasitized specimens and some of the 



