98 BRITISH TYBOGLYPHID^. 



The Passage between the Bursa Copulatrix and the 

 Receptaculum Seminis. PL B, fig. 8; PL C, 

 figs. 1, 11, bd. 



This, in all species which have been investigated on 

 the point, is a simple tube of a diameter somewhat 

 less than that of the bursa copulatrix, but doubtless 

 elastic ; it passes in a course which is not quite straight, 

 the tube being longer than the space it has to traverse ; 

 it enters the receptaculum seminis in the median line. 

 Nalepa says that the tube is chitinized, but this is 

 very slightly so, if at all, in the species which I have 

 examined. 



The Receptaculum Seminis. PL B, fig. 8; PL C, 



fig. 1, rs. 



This, in all species which have been investigated, is 

 a bladder-like organ, of a globular or elliptical form, 

 lying in the median line of the hind part of the 

 abdomen; its size varies greatly at different ages; 

 being quite small in the virgin female, while it may 

 become very large in the fertilised creature ; it then 

 has a transparent structureless wall; its contents 

 always appear as if contained in an inner sack ; this 

 appearance may however possibly arise from a 

 hardening of the periphery of the contained mass : 

 this mass consists of spermatozoa, almost round and 

 closely packed near to the entrance of the tube from 

 the bursa ; and of a finely granular substance, doubtless 

 the secretion of the male accessory glands, further in 

 the sack; if there be an inner sack it must be rup- 

 tured at some time or have a passage out of it which 

 I did not detect ; as the short tubes (ro), one on each 

 side of the receptaculum, which connect that organ 

 with the ovaries spring from the outer sack. 



Furstenburg * denied that the ? had any receptacu- 

 lum seminis. Robin saw the sack, and he probably 



* ' Die Kvatzmilben der Menschen und Thiere,' Leipzig, 1861, p. 195. 



