DEVELOPMENT. 



709 



-whales, and traces of this tabulation being visible in the human foetus 

 at birth. In the adult all the lobules are fused into a compact solid 

 organ. 



The suprarenal capsules originate in a mass of mesoblast just above 

 the kidneys ; soon after their first appearance they are very much 

 larger than the kidneys (see Fig. 497), but by the more rapid growth of 

 the latter this relation is soon reversed. 



The first appearance of the generative gland has been already de- 

 scribed : for some time it is impossible to determine whether an ovary or 

 testis will be developed from it; gradually however the special charac- 

 ters belonging to one of them appear, and in either case the organ soon 



WW3 M 



FIG. 497. Diagram showing the relations of the female (the left hand figure $ ) and of the 

 male (the right hand figure $ ) reproductive organs to the general plan (.the middle figure) of these 

 organs in the higher vertebrata (including man). Cl, cloaca; R, rectum; Bl, urinary bladder; 17, 

 ureter; K, kidney; Uh, urethra; G, genital gland, ovary, or testis; W, Wolffian body; Wd. Wolf- 

 fian duct; M, Miillerian duct; Pst, prostate gland; Cp, 

 Cc, corpus cavernosum. 



9, Cowper's gland; Csp, corpus spongiosum; 



In the female. V. vagina; Ut, uterus; Fp, Fallopian tube; Gt, Gaertner's duct; Pi\ parova- 

 rium; A, anus; Cc, Csp., clitoris. 

 In the male. 



(Huxley.) 



Csp, Cc, penis; Ut, uterus masculinis; Fs, vesiculaseminalis; Fd, vas deferens. 



begins to assume a relatively lower position in the body; the ovaries 

 being ultimately placed in the pelvis; while towards the end of foetal ex- 

 istence the testicles descend into the scrotum, the testicle entering the 

 internal inguinal ring in the seventh mouth of foetal life, and completing 

 its descent through the inguinal canal and external ring into the scrotum 

 by the end of the eighth month. A pouch of peritoneum, theprocessus 

 vaginalis, precedes it in its descent, and ultimately forms the tunica vagi- 



