130 STATES IN WHICH FATTY MATTER EXISTS. 



in the next lecture, we find adipose tissue with a 

 mere trace of connective tissue. 



183. (States in which fatty matter exists in the 

 body. But before I describe the characters of the 

 fat tissue, it is desirable to refer briefly to the different 

 forms or states in. which fatty or oily substances are 

 found ; for fat exists in the body of man and in the 

 higher animals in several different states. 



In the first place, there is scarcely a fluid or tissue 

 in the organism of any animal from which more or 

 less fat cannot be extracted by careful analysis. 

 Secondly, every form of bioplasm yields a minute 

 quantity of fatty matter. Thirdly, in many parts of 

 the body, little particles (globules and granules) of 

 actual fat can be seen by the microscope. Such 

 globules are present in immense numbers in every 

 kind of m'lk. They are to be detected in the epi- 

 thelial cells of the sebaceous glands. Oil globules 

 are embedded in the mucus of the air passages, and 

 are to be detected in the liver cells of all animals, 

 -while in some cases the liver cells seem to consist 

 almost entirely of fat. In disease every tissue in the 

 organism may be the seat of deposition of globules 

 of fatty matter. But, lasily, fatty matter, and of a 

 jrarticu'ar kind, is formed by special bioplasm. It 

 forms the chief constituent of a most important 

 tissue, adipose tissue, which accumulates in many 

 parts, filling up interstices between the muscles and 

 forming, at least in the infant, a tolerably even layer 

 beneath the skin of the body. This layer of sub- 

 cutaneous adipose tissue varies however in thickness 

 in different parts and at different ages. In some 

 few situatior s particularly where the skin is very 

 movable over the tissues bineath, as the skin of the 

 eyelids, there is no adipose tissue at all; or, in o*her 

 words, the areclar or connective tissue in the meshes 

 of which the adipose tissue is usually contained, is 

 in this and some other situations, destitute of that 



