THE METANEPHROS 



mesonephric duct. The secretory tubules and the capsules of the renal 

 corpuscles are differentiated from the isolated caudal end of the nephro- 

 genic cord and thus have a similiar origin as the mesonephric tubules. 



Mesonephric duct 



Outer zone^f nephrogenic cord 

 Inner zone of nephrogenic cord 

 Pelvis of kidney 



Hind-gut 



Bladder 



Cloacal membrane -^ 



FIG. 209. -^-Reconstruction of the anlages of the metanephros in a human embryo of about 9 



mm. (after Schreiner). 



Cranial pole tubule 



Cranial 



/%-' 



I jpole tubule 



/ y-v \Caudal 

 ^X VJ/ 'pole tubule 



Urete 



Cranial 

 pole tubule 



Pelvis' 



Caudal 

 pole tubule 



Ureter^ 



Secondary 



collecting 



tubules 



Tertiary collecting 

 tubule 



FIG. 210. Diagrams showing the development of the primitive pelvis, calyces and collecting 

 tubules of the metanephros (based on reconstructions by Schreiner and Felix). 



In embryos of about 5 mm. the mesonpheric duct makes a sharp bend 

 just before it joins the cloaca, and it is at the angle of this bend that the 

 ureteric evagination appears, dorsal and somewhat median in position 

 (Fig. 216, B, C). The bud grows at first dorsally, then cranially. Its 



