ANATOMY. 601 



The Reproductive Organs of the Adult. 



In the first volume of this work, at p. 1G2, I have 

 stated that I had not then ever seen a pair of Orihatidce 

 in the act of coition. I have not been more successful 

 since that time, although I have kept large numbers in 

 confinement, and have very frequently bred young, and 

 have observed the parents carefully. I have, how- 

 ever, ascertained one fact from which the mode of 

 impregnation may be more or less surmised with pro- 

 bability of correctness ; this fact is that there is in the 

 female an almost straight, extremely delicate, mem- 

 branous tube, starting from within the anal plates, and 

 leading direct to the central ovary. The tube arises 

 close above the chitinous piece which lies at the anterior 

 end of the anal opening and serves to prevent the plates 

 from being drawn within the body and also serves as 

 an attachment for muscles. A somewhat diagrammatic 

 representation of this tube in Notaspis lucorum is given 

 on PL LIII, fig. 10. It has been ascertained by Haller,* 

 Nalepa,t and myself J (the two last papers being since 

 the publication of vol. i of this work) that in the 

 TyTorjhiphidce- a sperm-duct, almost similar to thafc 

 above described but more distinct, leads from a bursa 

 copulatrix close to the anus to the ovary of the female. 

 It is true that in the Tiiroglyphidce a receptaculum 

 seminis is interposed in the course of the duct which 

 I have not found in the Oribatidce. With regard to 

 the bursa copulatrix being situated close to the anus, 

 see also the observations by myself and others as to 

 Gh/ciphagus (a genus of Tyroglyphidce), Bennaleichus, 

 &c., quoted in vol. i, p. 163. 



* ' Zur Kenntniss der Tyroglyphen und Verwandten," ' Zeitschr. f. 

 wiss. Zool.,' Bd. xxxiv, p. 288. 



t " Die Anatoraie der Tyroglyphen," ' Sitzgsber. der k. Akad. der 

 Wissensch. Wien,' Bd. xc, Abth. 1, p. 97 (1884); ibid., Bd. xcii, 

 Abth. 1, p. 116 (1885). 



X " On some undescribed Acari of tbe Genus Glyciphag2i8 found in 

 Moles' Nests," ' Journ. Linn. Soc. London,' Zool., vol. xix, p. 273. 



