706 METABOLISM 



taut to note that the exact locations of fat and carbohydrate in the he- 

 patic lobule are somewhat different in the two cases. 



A practical clinical application of the above work is found; in the fact 

 that fats will be more readily utilized by the body when they contain a 

 high percentage of unsaturated fatty acids. It is probably for this 

 reason that Norwegian cod-liver oil is of such undoubted nutritive value. 

 It is much more so than Newfoundland cod-liver oil, because in the prep- 

 aration of this variety oxidation occurs, which makes it no longer unsat- 

 urated. Fish oils in general are more unsaturated than other animal 

 oils, and are for this reason more nutritious. 



The fat in the tissues differs very materially from that of the liver or 

 the depots. Only 60 per cent of this fat consists of fatty acid, which is 

 present very largely as part of the lecithin molecule, thus accounting for 

 the high iodine value. Some is probably also present as simple glyceride, 

 in a highly unsaturated and therefore very fragile condition. 



