386 FAT METABOLISM. OBESITY 



the higher fatty acids (as Nasse has suggested) are there 

 prepared for further elaboration; on the other hand, as 

 Magnus-Levy believes, the accumulation of fat in the liver 

 may be an expression of a duty ascribed to this organ of hold- 

 ing in readiness reserve material available for any suddenly 

 introduced increase of metabolic exchange. "It is evident 

 that finely divided fat can be passed when needed into the 

 blood much more readily and quickly from the liver with its 

 full vascular arrangement, than from the fat globules of the 

 adipose cells of the subcutaneous tissue, which present so 

 small a surface in proportion to their contents. According 

 to this view the liver with its deposits both of glycogen and 

 of fat would have the office of providing material for combusr- 

 tion for the body at any time when there is a sudden increase 

 of demand put upon it. ' ' 18 



Formation of Fat from Sugar. A matter of much impor- 

 tance to the physiological procedure of metabolism is the 

 formation of fat from sugar. This subject may now be 

 somewhat more fully considered as the reverse process, the 

 formation of sugar from fat, has been discussed above 

 (v. supra, p. 240). 



The fact that carbohydrate is converted into fat in the 

 economy seems today quite axiomatic to us ; it is in fact one 

 of the few scientific points in physiological chemistry which 

 has passed into popular knowledge. Every layman realizes 

 in these days that people who want to avoid becoming too 

 obese must guard against eating too much bread and made 

 dishes. And yet it was at the expense of long continued and 

 difficult metabolic study that the fact of the formation of fat 

 from sugar was finally removed from any doubt. 19 The 



18 A Magnus-Levy, Noorden's Handb. d. Pathol. d. Stoffwechs., 2d ed., 1, 

 177-178, 1906. 



"Literature upon Fat Formation from Carbohydrates: G. Rosenfeld, 

 Ergebn. d. Physiol., 1, 666-671, 1902; R. Tigerstedt, Nagel's Handb. d, Physiol. 

 1, 513-516, 1905; A. Magnus-Levy, Noorden's Handb. d. Pathol. d. S'toffwechs., 

 2d ed., 1, 165-168, 1906; A. Magnus-Levy and L. F. Meyer, Handb. d. Biochem., 

 4, 449-450, 455-456, 472-474, 1909. 



