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 
Fic. 372.—Female urogenital Fic. 373.—Male urogenital 
organs of pigeon. organs of pigeon. 
K., Kidney with three lobes ; w., ureter ; T., testes; V7., base of inferior vena 
cl., cloaca; ov., ovary; od., oviduct ; cava; S.R., suprarenal bodies; K., 
/-t., funnel at end of oviduct ; 7.7.0d., kidneys with three lobes (x, 2, 3); 
rudimentary right oviduct. u., weter; v.d., vas deferens; vs., 
seminal vesicle ; c/., 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 
