THE METABOLISM OF FATS AND CARBOHYDRATES 137 



parts of the kidneys. Flakes of it occur in the mesentery 

 and on the surface of the heart. It is developed in the 

 deep eye-sockets. ^subjects better nourished there will 

 be more or less of this tissue widely distributed over the 

 body occupying a position between the skin and the 

 underlying muscles the so-called subcutaneous fat. 

 This may be indefinitely increased in the obese. Another 

 characteristic of obesity is the gathering of adipose tissue 

 in the great omentum, the sheet of membrane hanging 

 from the lower border of the stomach. When much fat 

 is present in this situation the ventral wall of the body has 

 a double burden, one layer of this reserve material out- 

 side and a second within the abdominal muscles. 



We shall postpone to a later time any discussion of the 

 factors which influence the accumulation of fat in the sys- 

 tem. A point previously made is to be insisted upon, that 

 the fat of the body is not derived solely, nor, indeed, chiefly, 

 from the fat of the food_. We shall presently consider to 

 what extent it is formed from the other food-stuffs. 

 Whether there is a great or only a moderate amount, it 

 will serve to maintain the activities of the muscles during 

 periods of insufficient feeding or absolute fasting. When 

 an animal has died from starvation but little fat can be 

 found in its tissues. The reduction of the fat presumably 

 present at the beginning of inanition has been estimated to 

 have reached 97 per cent, of the supply when death finally 

 supervenes. The power to endure starvation is naturally 

 greater for an animal or a man having a large initial store. 



For each species the body fat has a nearly constant 

 character. There is a certain ratio maintained between 

 the several fatty acids, and, as a result of this, a definite 

 melting-point. There cannot be such a diversity here, as is 

 the case with the proteins of different animals, but there 

 is a similar appearance of individuality. Accordingly, 

 when one animal preys upon another of a different species 

 and is nourished at the expense of its victim, it .does not 

 store precisely the form of fat which it has eaten, but 

 ^modifies it to conform to its own standard. The making 



