UROGENITAL SYSTEM. 
317 
Fic. 322.—Profile reconstructions of lizard (Lacerta agilis) (A) 16 mm. long; (B) 20mm. 
long; and (C) human embryo 115 mm. long, after Schreiner. a, allantois stalk; c, cloaca; 
cc, cranial collecting tubule; cd, caudal collecting tubule; &, permanent kidney (metanephros); 
mct, median collecting tubule; mf, metanephric (nephrogenous) tisssue; mtb, mesonephric 
tubules; pct, primary collecting tubule; gu, Wolffian duct (primitive ureter); 7, rectum; 
s, secondary collecting tubule; u, ureter; cm, u and pu, common portion of primitive and 
permanent ureters. 
FIG. 323.—Models of two stages in the development of tubules of kidney (metanephros) 
of man, after Stoerk. 6, Bowman’s capsule; c, collecting tubule; cm, connecting tubule; 
cv, convoluted tubule; #, Henle’s loop; i, intercalary tubule; /, lower arch; m, middle piece. 
