672 



BIRDS. 



In front of each kidney, at the base of the iliac vein, there lies a 

 suprarenal body. 



Reproductive system. The testes lie in front of the 

 kidneys. Like the ovary, they increase in size at the breed- 

 ing season, and dwindle afterwards; the sexual period in 



v.d 



FlG. 372. Female urogenital 

 organs of pigeon. 



A'., Kidney with three lobes ; u., ureter ; 

 /., cloaca; ov. t ovary; od., oviduct; 

 f.t., funnel at end of oviduct ; r.r.od., 

 rudimentary right oviduct. 



F IG - 373- Male urogenital 

 organs of pigeon. 



T., testes; V., base of inferior vena 

 cava; S.K., suprarenal bodies; AT., 

 kidne}^ with three lobes (i, 2, '3); 

 ., ureter; v.d., vas deferens; vs., 

 seminal vesicle ; cl., cloaca. 



birds being much more narrowly limited than in most other 

 Vertebrates. 



The spermatozoa pass from the testis into a vas deferens, 

 which lies to the outside of the corresponding ureter. The 

 vasa deferentia, slightly convoluted when full of sperms, and 

 with a posterior swelling or seminal vesicle, open separately 

 into the median compartment of the cloaca. 



In the adult pigeon, and in most birds, there is only one 



