ELEDONE. 507 
(2) In Sepia a branch from the gastric ganglion may 
be followed up the wall of the intestine to its tip. At the 
point where the ink duct joins the intestine this nerve 
gives off a very fine branch which runs down the wall of 
the duct and gland to the posterior end. This nerve 
regulates the secretion of pigment, while the visceral 
nerve branches control the muscular contraction of the 
ink sae (Girod). 
The ink sac has rather an elaborate vascular system. 
The abdominal aorta, running up from the heart to the 
intestine, gives off a vessel to the ink sac (Pl. VI, fig. 49, 
I.S.A.). This enters at its base, first giving off at each 
side a spirally curved vessel to the corresponding lobe of 
the pancreas (fig. 32, P.A.). Then it divides into four 
vessels, which become embedded in the wall of the ink 
sac and send branches to the internal glandular 
trabeculae. The ink duct also receives a small artery 
from the terminal portion of the intestinal vessel. 
The vein runs from the sac into the posterior part of 
the anterior vena cava (posterior hepatic vein). It is 
formed by the union of two vessels which run one on 
either side of the ink sac and unite at its base. On their 
way these receive branches from the sac, and much longer 
ones from the liver and pancreas (fig. 32, J.S.V.). 
Structure.—Cutting a sagittal section of the gland, 
the following portions may be seen:—(1) The basal 
glandular part (Pl. IV, fig. 26, J. gld.); (2) the reservoir 
above this (fig. 26, Res.) ; and (3) the duct, of about equal 
length with the gland. Its terminal portion hes external 
to the visceral envelope (fig. 32), and bears two internal 
valves, just near the anterior end. 
The glandular part, after being wel washed, will be 
seen to consist of numerous trabeculae, which branch and 
run into one another (fig. 26, ¢.). These are membranous, 
