6*6 



ANATOMY OF VERTEBRATES. 



384. In Rodcntia.- -This order offers transitional steps from 

 the foregoing type to the more common ( uterus bicornis,' with 

 single os tincne and vagina. In the Biscachia (JLagostomus tricho- 

 dacti/lus) the two uteri are distinct, and each opens into a separate 

 canal formed by a longitudinal septum continued about one-third 

 down the vagina. 1 In the Capybara, Sciuridcz and Leporidce, the 

 two ora tincae of the separate uteri open into the fundus of a 



common vagina, fig. 540, h, i. 

 In the Beaver there is one 

 large prominence, like an 

 6 os tinea?,' but the uteri ter- 

 minate thereon by separate 

 orifices. In MuridcR, the 

 Aguti, the Paca, the two 

 uteri blend into a short 

 common cavity, with one 

 opening into the vagina : 

 they are connected toge- 

 ther for some extent beyond 

 the confluent cavities, or 

 true l corpus uteri.' The 

 ovaries, which are elongat- 

 ed, subcompressed, and with 

 an even exterior, in the unexcited state, fig. 540, k, I, become 

 botryoidal when the ovisacs are developed with ripe ova, fig. 

 772, A, a, a'. 



In the Beaver the f pavilions' are small and simple : upon these 

 the oviducts are obliquely folded ; the uteri are long, straight, and 

 of uniform slender diameter when unimpregnated. The os tinea? 

 is followed by a series of irregular flat processes, which project 

 from the fore part of the vagina, gradually becoming smaller. 

 The urethra communicates with the vagina near its distal end : 

 the clitoris projects from a notch just beyond the urethra ; and in 

 front of the clitoris is the wide aperture common to the two 

 large preputial or ( castor ' bags : there are also smaller lobulated 

 masses beyond the bags. In the Rabbit the aperture of the 

 pavilion, ib. b' ', is more fimbriate and plicate than in the Beaver : 

 it is continued along the border of a shallow peritoneal capsule 

 extending from the further side of the ovary to the border of the 

 broad ligament. From the ovary the remnant of the ligament of 

 the primordial kidney ascends to the diaphragm. The oviduct, 



Female organs, Hare. cxxi'. 



1 ccxn". p. 177. 



