UROGENITAL SYSTEM. 309 
stome; the cilia, which may continue for some distance along the 
inside of the tubule, serving to create a current which carries the 
coelomic fluid into the tubule and thence outward. Farther along 
the tubule expands into a Malpighian or renal corpuscle (fig. 315). 
This consists of a vesicle (Bowman’s capsule), one side of which 
Fic. 314.—Diagram of conventionalized excretory tubule. , ascending limb of 
Henle’s loop; b, Bowman’s capsule of Malpighian body; c'—c?, first and second con- 
voluted tubules; ct, collecting tubule; d, descending limb of Henle’s loop; g, glomerulus 
of Malpighian body; with artery and vein; 4, Henle’s loop; n, nephrostome opening into 
coelom; x, entrance of other tubules into collecting duct. 
projects into the other, nearly filling the cavity. This inturned portion 
is the glomerulus. It consists of a network of capillary blood-vessels, 
supplied by an artery and drained by a vein. Beyond the connexion 
of the Malpighian body the tubule becomes contorted or convoluted 
and its cells are strongly glandular in character. This first convoluted 
tubule is succeeded by a nearly straight tract, folded once on itself into 
Fic. 315.—Diagram of renal (Malpighian) corpuscle. a, artery; b, Bowman’s capsule; 
. gi, glomerulus; ”, nephrostome; ¢, nephridial tubule; v, vein. 
the descending and ascending limbs of Henle’s loop. Next follows 
the second convoluted tubule, which passes by means of a short 
connecting tubule into a non-glandular collecting tubule into which 
several other systems of excretory tubules enter, and which leads 
more or less directly into the urinary duct which conveys the waste 
from the excretory organ to the exterior. 
