IIO ALLEN 
cephalad through the center of the kidney until the kidney 
forks, when it follows the right fork. In the region of the last 
branchial arch it unites with the right jugular in forming the 
right precava (Pls. I and II, figs. 5 and 12; Prec.V.) or the 
ductus Cuvierté as it is often called, which encircles the right 
side of the cesophagus and empties into the sinus venosus in 
front of the subclavian sinus. 
(c) Other Vessels Emptying into the Kidney. — Beside the 
posterior mesenteric and caudal veins there are several other 
vessels, which penetrate the kidney and reach the right cardinal 
in one way or another. 
First under this head might be mentioned the spermatic vezns. 
In the female (fig. 1) numerous branches arise from the lateral 
surfaces of the ovaries and unite in a longitudinal vessel, that 
has its origin from the anterior surface of the urinary bladder 
and the oviduct. From this longitudinal vessel at least two 
spermatic veins (fig. 1; Sper. V.) have their origin; passing dor- 
sad they terminate in one way or another in the kidney: they 
may empty directly into the right cardinal, or the renal portal 
vein, or they may reach the right cardinal through the efferent 
renal veins. Inthe male (see fig. 10) there is no longitudinal 
trunk, and the spermatic veins arise directly from numerous 
branches coming from the inner surface of the testes. In this 
specimen the most anterior spermatic vein emptied into an affer- 
ent renal vein, the second one broke up into capillaries, and the 
last 2 joined the posterior mesenteric vein within the kidney. 
The zeurals as in the caudal region drain the region of 2 myo- 
tomes, passing ventrad between the neural lymphatic vessel and 
the neural spine, they penetrate the dorsal wall of the kidney, but 
instead of emptying directly into the right cardinal, break up 
into capillaries that reunite in the efferent renal veins. The 
intercostal veins (fig. 1; Intc.V.) corresponding to the hemal 
veins of the caudal region, arise from 2 myotomes of the thor- 
acic walls; passing dorsad behind the intercostal lymphatic 
vessel they penetrate the ventro-lateral edge of the kidney, 
break up into capillaries, and reach the right cardinal through 
the efferent renal veins. In the cephalic part of the thoracic 
wall they anastomose ventrally with the ventral intercostal 
