no 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 

 7-ight -precava (Pis. I and II, figs. 5 and 12 ; Prec.V.) or the 

 diicUis Cuvierii as it is often called, which encircles the right 

 side of the oesophagus 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 sper^natic veins. 

 In the female (fig. i) 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. i ; 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. In the 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 neiirals as in the caudal region drain the region of 2 m3'o- 

 tomes, passing ventrad between the neural h^nphatic 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. i ; Intc.V.) corresponding to the haemal 

 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 



