GENERAL ANATOMY OF THE GLANDULAR SYSTEM. 



83 



opment of ihe follicular sac, and \\\& excretory tube. In these 

 compound or conglomerate glands, such as the lachrymal, 

 mammary, salivary glands, pancreas, liver, etc., the excretory 

 tube is longer and ramifies in the manner of a tree. In some, 

 the tubes ramify with a certain degree of regularity, as in the 

 mammary gland, represented in the following figure. In some 

 as in the tubular glands, the kidneys and testes, the tubes 

 which begin as blind sacs on the periphery of the organs, are 

 tortuous, looped and convoluted at their commencement, and 

 often at the same time inextricably intervolved with the capillary 

 blood-vessels, lymphatics and nerves. 

 Fig. 145.* 



— The divisions given off by the main duct of a conglomerate 

 gland divide again by giving off side branches ; these divide 

 and subdivide in like manner in their turn, till finally, a subor- 

 dinate branch of minute size terminates in a cluster of blind 

 pouches or follicles, which are invested on their outer face by 

 cellular tissue, and capillary vessels, and form one of the 

 acini or granules of a gland. A collection of these acini, which 

 correspond to a particular division of the excretory duct, will 

 necessarily be a little separated from other parts of the gland, 

 and is called a lobule. This is the arrangement in all the 



* The diameter of the cells or terminal cavities of the lactiferous ducts, is 

 large, compared with those of many other glands ; it is from ten to thirty-five 

 times greater, according to Mailer, than that of the smallest capillary vessels 

 in the human body. — p. 



