The Urinogenital System. 



95 



presence of this kidney in embryo mammals, together with its duct, 

 determines the form and connections of the ductus deferens with 

 the terminal portions of the urinary system. The pronephros, on 

 the other hand^is a vestigial kidney in all -vertebrates, but its duct 



Fig. 52. The male urinogenital ducts and related 

 structures, viewed from the lateral surface. After Rau- 

 ther: a., anal aperture; bu., bulbourethral gland; c.c., 

 corpus cavernosum; d.d., ductus deferens; g.a., anal 

 (rectal) gland; g.i., inguinal gland; g.p., glans penis; par., 

 paraprostatic glands; ,pr., prpstate; r., rectum; ut., ureter; 

 U.V., urethra (membranous portion); v.s., seminal vesicle; 

 V.U., urinary bladder. 



system, open proximally to the body cavity plays an important 

 part in the formation of the oviduct in the female of all classes of 

 vertebrates. The development of the kidney reveals a condition, 

 also suggested in a less perfect way by the mesonephros, in which 

 it is shown that the primary connections of the kidney tubules are 



