2 I. INTRODUCTION 



although a large amount of work is in progress on the mechanism of syn- 

 thesis and on its metabolism in the animal body. 



The chemical approach to the subject of lipids has been made in the first 

 volume of this work. In the current volumes, this aspect will be touched 

 upon only insofar as the information contributes to the problem under 

 discussion. 



The biochemistry of the lipids will be considered from the classical view- 

 points: First, in Volume II, the subject of lipids will be discussed from the 

 standpoint of digestion and absorption in the gastrointestinal tract. This 

 will be followed by a review of their transport in the blood, with sections 

 on the variations to be found in health and disease. The discussion will 

 next center on the storage of lipids in the tissues in general, with a con- 

 sideration of the factors which alter fat deposition in such tissues. The 

 nature of the fat deposited in specific tissues and organs will be the subject 

 of another chapter. In each chapter, the changes of the fats, phospholipids, 

 sterols, carotenoids, and fat-soluble vitamins will be considered in separate 

 sections. Data on the deposition of carotenoids and fat-soluble vitamins 

 are not included in the discussion of storage, since they can more appropri- 

 ately be discussed in the section on nutritional aspects of these compounds. 



In Volume III, the intermediary metabolism of the lipids will be described 

 from the viewpoint of their synthesis, oxidation, and metabolism under 

 biological conditions. The role of the several types of lipids in nutrition 

 will be covered in another section of Volume III. 



