236 



ZOOTOMY. 



231. In the male the genital papillae (Fig. 52, v.d') 

 conical elevations just external to the urinary apertures : on 

 their apices are the apertures of the vasa deferentia. 



232. In the female the aperture of the left oviduct 



(Fig. 53, l.od'), a considerable opening just external to that 

 of the left ureter : the rudimentary right oviduct has a 



ur.l«'d 



Fig. 55- — Columba livia. The cloacci of a young female. A, opened 

 from the ventral arpett ; B, in long-itudinal .section (nat. size). 



b.f, bursa Fabricii : *./', its opening into posterior chamber of cloaca : 

 cl.i, anterior, c!.2, middle, and c1.t„ po<;terior, chamber of cloaca : «/, 

 opening cf oviducts into middle chamber of cloaca : r, rectum : iir, 

 opening of ureters into middle chamber of cloaca. 



small opening {r.od') similarly situated on the right side : 

 in the young bird the two apertures are of equal size 

 (Fig. 55, od). 



233. The aperture of the bursa Fabricii (Fig. 55, b.f), a small, 

 crescentic opening in the middle of the dorsal wall of the posterior 

 chamber : by drawing the cloaca backwards, and gradually dissecting it 

 away from its attachments, the bursa is seen as an ovoid, somewhat 

 flattened sac (b-f), with glandular walls, situated between the dorsal 

 wall of the cloaca and the roof of the pelvic cavity : it is best de- 

 veloped in young individuals, when it may attain a length of a quarter 

 to three-quarters of an inch ; in the adult it is usually absent. 



