LOLIGO PEALII LESUEUR 251 



median mantle artery running to the median line of the mantle, 

 if not severed during the dissection, will be seen running ob- 

 liquely to your right and terminating in the mantle where it 

 splits up into finer branches. The two small papillae at the 

 base of the rectum are provided each with an opening. These 

 openings are the nephridiopores. The thin, bilobed nephridial 

 sac occupies all the space between the base of the rectum and 

 the branchial hearts. Through the wall of the sac the two 

 urinary glands can be clearly discerned. Behind the left bran- 

 chial heart (on your right) the following organs can be seen 

 through the body wall (visceral sac) : the coiled vesicula semin- 

 alis, the spermatophoric sac and, more toward the median line, 

 the large testis extending to the rear end of the sac. Make a full 

 page drawing showing all organs in situ. 



9. Cut the lateral valves on each side of the funnel along the 

 infundibular cartilage. Pull the funnel gently with your fingers 

 until you have completely removed it together with its retrac- 

 tors. Open its lower wall along the median line and fasten the 

 sides down with pins. Make a drawing showing the infundibular 

 valve, the four organs of V err ill and the retractors. 



10. The removal of the funnel with its retractors has exposed 

 to view the cephalic retractors with the oesophagus and liver be- 

 tween them, and the two large stellate ganglia situated on the 

 mantle under the cephalic retractors on the level of the tips of 

 the gills. The body wall and the nephridial sac should now be 

 removed with the aid of a forceps. When this has been done, 

 pass the end of a curved forceps between the posterior vena cava 

 of each side and the corresponding lateral mantle vein and sep- 

 arate the vessels without tearing them. In a similar manner 

 separate the ink-sac from the rectum leaving intact its attach- 

 ment to the anal chamber and push the ink-sac to your right. 

 Separate the penis from the underlying tissues ; push the stomach 

 pouch to the left exposing the end of the testis with the terminal 

 tendon. Find the single splanchnic ganglion on the rectum near 

 its base. 



