86 Invertebrate Zoology. 



liver, or mesenteric gland, into the intestine. What is its 

 extent? Cut the gland open and see if it has a lumen. 

 Does the lumen communicate with the intestine? What is 

 the plan upon which the organ is built up. 



Carefully finish the drawing of the alimentary tract and 

 its diverticula. 



Remove the entire alimentary tract and float it out in 

 clean water. Dissect away the anterior wall of the stomach 

 and wash out the contents. Artificially work the gastric 

 teeth together, thus demonstrating their function. Do you 

 notice any apparatus that prevents the larger fragments of 

 food from entering the delicate intestine ? Do you find any 

 organs which might, in function, distinguish between the 

 nutritious and non-nutritious contents of the stomach ? Are 

 sensory hairs present in the oesophagus? 



Slit open the intestine, caecum, and rectum. Do you find 

 any local differences in the lining membrane of the three 

 portions ? 



Make a drawing of the interior of the right half of the 

 stomach. 



Excretory System. With great care remove the left 

 green-gland. Do you find the following parts : A smaller, 

 ventral, glandular portion, of a deep green color in the 

 living animal? A very large saccular portion, the deli- 

 cate diverticula of which extend as lobes over the ante- 

 rior and lateral walls of the stomach? The urinary 

 duct, leading to the opening at the base of the second 

 antennae ? 



Reproductive System. This may be worked out on 

 the side of the animal which has not yet been injured. If the 



