A SQUID 131 
prevented from passing into it from the stomach by valves. 
Loosen the stomach, noticing that it is bound to the ovary or 
testis by an artery, the genital artery. At the forward end of 
the stomach are the intestine and the esophagus, side by side; 
the former passes between the two halves of the pancreas and 
ends with the rectum; the cesophagus goes forward side by side 
with the anterior aorta to the middle of the large liver and 
passes through it in company with the aorta. The cesophagus 
is easily found by turning the stomach over. A small ganglion 
with radiating nerves will be seen by the side of the esophagus 
near its junction with the stomach. 
The liver is an elongated body lying between the retractor 
muscles of the head and of the siphon; two ducts emerge 
from it and pass through the pancreas to the stomach pouch. 
Loosen and remove the connective tissue around the liver and 
raise it up; the cesophagus and the aorta will be seen to pass 
through it towards the back of the animal and then forward to 
the head. 
Remove the siphon and split the wall of the head; trace the 
esophagus to its forward end. It will be seen to pass through the 
ganglionic mass which constitutes the central nervous system, 
and which is surrounded by a hard cartilaginous capsule. For- 
ward of this it meets and ends in the bulbular pharynx. Near 
the forward end of the liver, and resting upon the esophagus, 
will be seen the median salivary gland, the duct of which may be 
traced to the pharynx; near the hinder end of the pharynx is 
a pair of smaller salivary glands, which also communicate with it. 
Trace their ducts to the end. The alimentary canal will thus be 
seen to consist of the following organs: the muscular pharynx, 
with which a pair of small salivary glands and a single large 
salivary gland communicate; the narrow esophagus; the thick- 
walled stomach; the stomach pouch, which communicates with the 
stomach by a valved opening; the elongated liver, which com- 
municates with the stomach pouch by two long ducts; the bilobed 
