132 DISTRIBUTION OF BLOOD TO ADIPOSE TISSUE. 



plasm) which is to take part in its formation can be 

 distinguished from that which is to give rise to other 

 textures. The several stages through which adipose 

 tissue passes in its development may be as clearly 

 made out in any young mammal at the time of its 

 birth as during the earlier periods of its development. 

 ISTay, in certain cases it may be studied in an em- 

 bryonic condition even in the adult. Excellent spe- 

 cimens which illustrate every stage of the process may 

 be obtained easily from the areolar tissue under the 

 skin of some parts of the body of the fully formed 

 frog. 



186. Of tbe distribution of blood to adipose tissue. 

 A tissue which undergoes great alterations in volume 

 so quickly as this, ought to have a very intimate re- 

 lationship to the blood from which it derives the 

 elements entering into its composition. This is, 

 indeed, the case, for adipose tissue is very largely sup- 

 plied with blood, and in corpulent persons who make 

 fat fast, the greater part of the blood of the body is 

 probably distributed to the adipose tissue, and other 

 tissues and organs may even suffer in nutrition. The 

 muscles may become weak, and waste, and the nerves 

 be impaired, owing to the nutrient material of the blood 

 being unduly appropriated by the bioplasm of the 

 adipose tissue. 



187. Vessels. Arteries, capillaries, and veins, are 

 developed pari passu with adipose tissue. And there 

 is not an instance among vertebrate animals of the 

 occurrence of adipose tissue destitute of vessels. The 

 vascularity of the medulla or marrow of bones is re- 

 markable. The rate at which adipose tissue grows, 

 in certain cases, is very striking, and probably the 

 animal in. which it is produced most quickly is the 

 well bred young pig, whose adipose tissue doubles in 

 weight in the course of a very few weeks. In the 

 meshes of the capillary network of very young adipose 

 tissue may be seen the little masses of bioplasm, which 



