MisctllancoHif. HO 



before they open into the vesicula Btinintilis, lo^e their tyi)i(al 

 epitluliiini and form 



7. Tlic special ghiiidular portion, which servos to secrete tlie 

 chitinoua substance for the memltrano of the Hpermato])liores ; 



8. The semen enters the sexual organs of llae female in the form 

 of oval and somewhat flattened spermatophores. 



The female sexual organs are constructed in the following 

 manner : — 



1. The external genital aperture has the same appearance as iu 

 the male ; 



2. The vagina is clothed with a thick chitinized iutima ; 



3. Tlic receptacula scniinis are re])resented by two vesicles with 

 chitinized intima, and oj)eu into the vagina in the neighbouihood of 

 the genital aperture ; 



4. On its posterior wall the uterus is provided with two auricu- 

 late appendages, which do not differ in histological structure from 

 the remaining portions of the uterus, and, as it appears, play no 

 physiological part whatever ; 



5. The oviducts pass immediately into the ovaries. The walls of 

 these two sections are longitudinally folded, in consequence of which 

 when the sexual organs become hlled with ova or s])ermato])hores 

 they are capable of considerable expansion, whereby the cavitv of 

 the organs is increased ; they consist of (a) the external adipose 

 layer, (h) the circular musculature, (c) the longitudinal musculature, 

 {d) the tunica propria, and {e) the columnar ejiithelium. In the 

 first three layers an abundant ramitication of trachete is observable ; 



6. The ova develop from a special epithelial layer, which clothes 

 the wall of the ovaries on the interior; 



7. The ripe ova, which already lie in the follicles which become 

 evaginated, have a so-called " stylum " * ; 



8. In the cavity of the ovaries and of the oviducts there may bo 

 observed a considerable number of free cells which bear a strong 

 resemblance to the blood-corpuscles. The cells possess the power 

 of amoeboid movement and exhibit figures of karyokinetic division. 

 They demolish the envelopes of the spermatophores, thereby libera- 

 ting the spermatozoa, and at the same time destroy the superfluous 

 Bpermatozoa and the unfertilized ova f ; 



9. The ripe ova fall into the cavity of the ovaries, where the 

 development of the embryo is completed ; 



10. Even before the formation of the rudiments of the ap])cn- 

 dages a great ditierence in form is noticeable between the thoracic 



* Bcrtkau, " Ueber den Generationsapparat der Araueiden,'' Arcliiv f. 

 Naturgescbichte, 1875, p. 2-Jo. 



t Corpuscles of this kind have been described by Prof. A. Schneider in 

 Xephflis, Aiilosfomian, and Ilinido — A. Schneider, " Ueber die Aiitlusung 

 der Eier and Spfnnatozoen in dfu f iesohlecht^organen," Znol. \m. IngO, 

 no. 4f). p. 19. 



