442 NUTRITION ANIMAL HEAT AND FORCE. 



a comparatively low diet, while others deposit but little adipose matter, even 

 when the regimen is abundant. It is to be noted, however, that the former 

 are generally addicted to the use of starchy, saccharine and fatty articles of 

 food, while the latter consume a greater proportion of nitrogenized matter. 

 It is not an uncommon remai^f that the habit of taking large quantities of 

 liquids favors the formation of fat ; but it is not easy to find any scientific 

 basis for such an opinion. The formation of fat by any particular organ or 

 organs in the body has not been determined. 



Condition under which Fat exists in the Organism. It is said that fat, 

 combined with phosphorus, is united with nitrogenized matter in the sub- 

 stance of the nervous tissue ; but its condition here is not well understood. 

 A small quantity of fat is contained in the blood-corpuscles and is held in 

 solution in the bile ; but with these exceptions, fat always exists in the body 

 isolated and un combined with nitrogenized matter, in the form of granules 

 or globules and of adipose tissue. The three varieties of fat (stearine, palmi- 

 tine and oleine) are here combined in different proportions, which is the 

 cause of the differences in its consistence in different situations. 



Physiological Anatomy of Adipose Tissue. Adipose tissue is found in 

 abundance in the interstices of the subcutaneous areolar tissue, where it is 

 sometimes known as the panniculus adiposus. It is not, however, to be con- 

 founded with the so-called cellular or areolar tissue, and is simply associated 

 with it without being one of its essential parts; for the areolar tissue is 

 abundant in certain situations, as the eyelids and scrotum, where there is no 

 adipose matter, and adipose tissue exists sometimes, as in the marrow of the 

 bones, without any areolar tissue. 



Adipose tissue is widely distributed in the body and has important me- 

 chanical uses. Its anatomical element is a rounded or ovoid vesicle, -g-J-g- to 

 g-J-g- of an inch (30 to 80 /x.) in diameter, composed of a delicate, structureless 

 membrane, ^-g-J-oD of an inch (1 /x) thick, enclosing fluid contents. The 

 membrane sometimes presents a small nucleus attached to its inner surface. 

 The contents of the vesicles are a minute quantity of an albuminoid fluid 

 moistening the internal surface of the membrane, and a mixture of oleine, 

 palmitine and stearine, nearly liquid at the temperature of the body but 

 becoming harder on cooling. Little rosettes of acicular crystals of palmitine 

 are frequently observed in the fat- vesicles at a low temperature. The quan- 

 tity of fat in a man of ordinary development equals about one-twentieth of 

 the weight of the body (Carpenter). The adipose vesicles are collected into 

 little lobules, -fa to of an inch (1 to 6 mm.) in diameter, which are sur : 

 rounded by a rather wide net- work of capillary blood-vessels. Close examina- 

 tion of these vessels shows that they frequently surround individual fat-cells, 

 in the form of single loops. There is no distribution of nerves or lymphatics 

 to the elements of adipose tissue. 



Conditions which influence Nutrition. Physiologists know more con- 

 cerning the conditions that influence the general process of nutrition than 

 about the nature of the process itself. It will be seen, for example, in studying 

 the nervous system, that there are nerves which regulate, to a certain extent, 



