LOLIGO 



157 



ach a rather large opening leads into a thin-walled blind sac, 

 the visceral sac. The latter, when filled with partly digested 

 food, as it frequently is, extends posteriorly to the end of the 

 body and occupies a considerable part of the conical portion 

 of the body. When empty, it is quite small and incon- 

 spicuous. | 



The intestine leaves the stomach very near the point where 

 the esophagus enters, and just anterior to the opening that 

 leads into the visceral sac. It passes ventrally, and becomes 

 visible from the surface, where its position has already been 

 noted. 



Draw a figure showing the digestive system. 



Cut a median sagittal section of the buccal mass, and 

 notice the mouth cavity, the jaws, the muscles that move 

 the jaws, the tongue, and the position of the radula. Is the 

 radula arranged in the strap-over-pulley manner that it is in 

 Busyconf 



Draw a figure of the section. 



Male Reproductive System. — 1. The testis (morphologic- 

 ally the left) is large, white, and flattened, and lies far back 

 in the pointed end of the body. It is enclosed in a sheath 

 which serves to collect the liberated sperm. 



2. Just anterior to the testis is a small rounded vesicle, 

 the ampulla, which is the point of origin of the vas deferens. 



3. The vas deferens is a plaited slender tube, which being 

 packed with sperm is opaque white. It extends from the am- 

 pulla along the right side of a large sac to be referred to later, 

 the spermatophoric sac, to and beneath (dorsal to) the sper- 

 matophoric organ, where it joins a portion of the organ on its 

 left side about one third the length of the organ back from 

 its anterior end. Remove the left gill and branchial heart and 

 strip away the thin tissue that covers the vas deferens and 

 spermatophoric organ, being careful not to injure either. 

 Carefully lift the right ventral side of the spermatophoric 

 organ and see where the vas deferens enters it. Drop the 

 spermatophoric organ into position again. 



