404 



COMPARATIVE ANATOMY 



Fig. 333. — Diagram of possible connexions of coelom with the exterior, c, coelonx; 

 cU cloaca; g, glomerulus of kidney; i, intestine; n, nephrostome; pa, porus abdominalis. 

 (From Kingsley's "Comparative Anatomy of Vertebrates," modified after Bles.) 



•GLOMERULU: 



NEPHROSTOME' 



.PRONEPHRIC 

 TUBULES 



A. PRONEPHROS 



WOLFFIAN DUCT. 



B. MESONEPHROS 



K«;SONEPHR IC 

 TUBULES 



AFFERENT ARTERIOLE 

 EFFERENT ARTERIOLE 



GLOMERULUS 



NEPHROSTOME 



MESONEPHRIC 

 TUBULE 



-'^'--"■-^■"■■^-'••■"'''^ 



■WOLFFIAN DUCT 



^aa^l!^.-R^^...j^ai.^-,.^-.^-...,>^^„-...„^u-U;.t.-.. .>»,..;. :...■„.;, u:;,^.jj;v.i^>vi 



C MESONEPHROS D. METANEPHROS 



Fig. 334. — Diagrams illustrating the relations of A, pro-, B-C meso-, and D, 

 metanephridial tubules. The primary or pronephric tubules remove wastes from the 

 body -cavity, while the mesonephric tubules get their wastes directly from the blood; 

 many of them, however, retain the original connexion with the coelom. The meta- 

 nephric tubules lose all connexion with the coelom. (Redrawn after Corning) 



