248 



STBTJCTUBE OF GLANDS. 



[ 420. The best picture we 

 possess of the vast variety existing 

 in the structural connection of the 

 several parts of the glandular skele- 

 ton, is in the secreting organs of in- 

 sects, particularly the salivary glands 

 (fig. 252). Here we observe the most 

 elegant and singular forms, having 

 frequently much of the vegetable 

 character in their appearance. The 

 salivary glands present themselves 

 now as filiform canals (fig. 252, B), 

 now thicker and convoluted, now 

 with a sacculate end (c), here ex- 

 tending into a simple (E) or a 

 double vesicle (M), there branched 



Fig. 249. Sudoriparous gland from the palm of the hand of a young 

 person eighteen years of age. A, a gland entire with its excretory duct, 

 magnified forty times ; a, a, the convoluted canals forming the gland, and 

 from which two excretory ducts arise, b, b, which unite to form the single 

 spiral duct, which, at c, passes through the laminae of the epidermis, and 

 opens on the surface at d ; c, c, surrounding fat cells. B, the same gland 

 more highly magnified. Around the canal of the gland play the vessels, 

 i, b. C, a few fat-globules from the emptied fat-cells. 



