Arteries. 
831 
exterior and to the various openings, it has been divided into 
three parts, which will be spoken of as the anterior, middle and 
posterior thirds; each third is approximately of the same 
length. 
ARTERIES. 
From the anterior end of the heart five arteries are given off; 
three near the dorsal border and two but a short distance below 
them. (Fig. 4, PI. V.) At the posterior ends of the heart only 
one artery is given off; this arises near the ventral border. 
(Fig. 2, PI. V.) 
Of the five arteries which arise from the anterior end of the 
heart, the three superior do not separate from each other im¬ 
mediately after immerging from the heart, but are bound to¬ 
gether for some little distance; eventually they become distinct 
vessels and have independent distribution. (Figs. 1 and 4, 
PI. V.) 
The middle of these three arteries is the ophthalmic, often 
called by the German authors the unpaired “Kopfaorta. ” This 
is the smallest of the three; it runs directly forwards, over the 
stomach, and is distributed to the brain and eyes. The other 
two are the antennary arteries; they pass forward and outward 
around the stomach and are distributed to the antennae. 
The remaining two of the five anterior arteries are situated 
ventrally from the three just described, near the center of the 
anterior end. (Fig. 4, PI. V.) They arise close to each other 
and separate soon after leaving the heart. They are the hepatic 
arteries. Their course is outward, downward and forward, 
being distributed, as their name implies, to the liver. In size 
they correspond with the antennary. 
The single artery arising from the posterior end of the heart 
is the superior abdominal, or posterior aorta. It is the largest 
artery arising from the heart; it passes backward into the ab¬ 
domen and is situated dorsal to the intestine. It gives off 
ventrally quite a large branch, the sternal artery. The supe¬ 
rior abdominal arises from a funnel-shaped prolongation of the 
heart (Fig. 2, PI. V), the artery forming the stem of the fun¬ 
nel. Following Huxley’s description, the sternal artery is said, 
