78 ALLEN 
renal arteries and finally breaks up on the posterior end of the 
air-bladder. The single spermatic artery (P1. IV, fig. 31; Sper.- 
A.), which performs part of the function of the urinary bladder 
artery of Ophzodon is given off from the aorta immediately in 
front of the point where the caudal vein penetrates the kidney. 
Near its source it sends off an intercostal artery (see fig. 31). 
It then follows along the posterior margin of the kidney, to the 
right of the caudal vein, and passing between the suprarenal 
bodies,’ supplies each with a branch. The spermatic artery 
then continues ventrad between the kidney and the reproduc- 
tive organs, gives off caudad the wrznary bladder artery (fig. 
31, Ur.Bl.A.), which is the only artery observed for the bladder. 
When the genital organs are reached, the spermatic artery 
anastomoses with the 2 anterior spermatic arteries already de- 
scribed under the head of the mesenteric artery. 
VII. PERIPHERAL DISTRIBUTION OF THE VEINS. 
The veins in general follow their corresponding arterial 
trunks, but not so closely as they do the nerves. There is 
much less literature on the veins than on the arteries. In Se- 
lachians where it is so much more difficult to inject the veins 
this is not strange, but with the Teleosts no more difficulty is 
experienced in injecting the veins. Generally the whole venous 
system can be satisfactorily injected from one point. (See 
under paragraph on technique). 
1. fugular Vetns. 
These large sinus-like vessels (Pls. I and II, figs. 1, 5, 15 
and 16; J.V.), which are much longer than the corresponding 
common carotid arteries, arise in front of the prootic process 
from 3 principal trunks (see fig. 15). The external jugulars, 
coming from the facial region; the internal jugulars, coming 
from the eye, eye-muscles, and brain; and the orbito-nasal 
vein. Each jugular immediately enters the foramen formed 
by the prootic process and in its course through this foramen it 
is a rather small vessel lying directly above the external carotid 
1The suprarenal bodies are situated further caudad on the kidney than in 
Ophtodon. 
