102 GENERAL ANATOMY OF THE TISSUES. 



lopmeut (lungs, small intestinal glands), others are at first 

 hollow, but afterwards increase by the addition of solid out- 

 growths (liver) ; others, again, are solid from the very first, con- 

 tinue to grow in this condition, and only secondarily come to 

 possess cavities (cutaneous glands, racemose glands). The 

 nutrition of the glands goes on with great energy, and they 

 belong to the most vascular organs of the body. Except in the 

 uterine glands, no regeneration of the glandular substance takes 

 place, but hypertrophy occurs in them, and even the accidental 

 formation of minute glands. 



The true glands of the human body may, according to the form 

 of their ultimate elements, above described, be divided as follows : 



1. Glands with closed glandular vesicles, which dehisce 

 periodically. Ovary, follicles of the uterus. 



2. Glands whose parenchyma cotisists of cells united into a 

 network. Liver. 



3. Racemose glands, in which, rounded and elongated 

 glandular vesicles are seated upon the ultimate ends of the 

 excretory ducts. 



a. simple, with one or few glandular lobules. Mucous glands, 

 sebaceous glands, Meibomian glands. 



b. composite, with many glandular lobules. Lachrymal glands, 

 salivary glands, pancreas, prostate, Cowper's and Bartholini's 

 glands, lacteal glands, lungs. 



4. Tubular glands, whose secreting elements have the form of 

 canals. 



a. simple, consisting of only one or a few csecal tubes. 

 Tubular glands of the stomach and intestine, uterine glands, 

 sudoriparous and ceruminous glands. 



b. composite, with many branched glandular canals, which 

 may also be united into a network. Testis, kidney. 



[The forms of the glands of animals, notwithstanding their 

 variety, may, with few exceptions, be brought under one of the 

 four categories here established. The following are worthy of par- 

 ticular notice : 1 . The glandular cells, with peculiar excretory 

 ducts, to be found in some Articulata, which either, singly, form 

 glands, or are united together in numbers by a membrana pro- 

 pria. 2. The occurrence of a structureless, chitinous membrana 

 intima in many glands of the Articulata. 3. The formation of 



