52 



Cutaneous (or tegumentary) glands. 



Scattered throughout the connective tissue, near the 

 basement membrane, are globular masses of cells, each 

 cellular clump being connected with the exterior by a fine 

 duct. These are the cutaneous glands. Each cell of the 

 globular mass is in contact with a small cavity on its 

 inner side. This central cavity of the glandular mass 

 receives the secretion from the various cells. The cavity is 

 connected with the duct, and thus the glandular secretion 

 is enabled to pass to the exterior. The duct is lined by 

 a tine protoplasmic wall. The wall of the duct probably 

 represents a single cell, in which case the cavity of the 

 duct is intracellular. The gland cells and the duct cell 

 are all modified epidermal cells. 



The cutaneous glands are scattered throughout the 

 integument, and in some regions are extraordinarily 

 abundant. The glands present in the mandibles and in 

 the walls of the oesophagus, and also those in the hind- 

 gut, have a similar structure to the ordinary glands on the 

 surface of the body. They are, in fact, modified cutaneous 

 tegumentary glands. 



Immediately in front of the mouth there is a compact 

 mass of cutaneous glands at each side, which open on the 

 surface of the epistoma. These glands have the structure 

 of the typical cutaneous glands, but are extremely large. 

 They are about four times as large as those present in the 

 walls of the oesophagus (see section on Alimentary 

 Canal). Similar glands are found also in the metastoma, 

 packed very closely together. Herrick* has also observed 

 them in the same regions in the lobster. (See fig. 60.) 



In the floor of the branchial chamber there is a well- 

 defined transverse ridge lying in front of the inhalent 



* Herrick. "The American Lobster." Bull. U.S. Fish Com., 

 Vol. XV., 1895. 



