PHYSIOLOGICAL 109 



of the cells becoming gradually displaced while the nucleus is 

 pushed to one side, coming to lie against the cell membrane. 

 The fat cell formed in this way grows to be very much bigger 

 than the original protoplasmic cell, and the large collections of 

 fat cells become packed closely together, being only separated 

 by very thin membranes and forming adipose tissue which may 

 be many cells in depth. This is what occurs in the normal 

 process of fattening. In other cases where the fat formation 

 has been carried to excess the cells of other kinds of tissue 

 such as muscle become the repositories of fat which interfere 

 with the discharge of the normal functional activities. Such is 

 the condition occurring in fatty degeneration which when it 

 affects the tissues forming the wall of the heart is a source of 

 danger to the life of the animal. 



Apart from definite degenerative change which does not usually 

 occur until comparatively late in life, the adipose tissue formed 

 in a fattening bullock may be considered under three heads. 



Firstly, there is the fat laid on in and beneath the dermis or 

 deeper layer of skin and upon the underlying muscles. Thus 

 if we take a rib of beef as cut in a butcher's shop we find that 

 the two principal outside muscles which are seen in cross- 

 section in the "joint," the trapezius which lies dorsally (i.e. 

 towards the spine of the vertebra) and the latissimus dorsi 

 which lies ventrally beginning where the trapezius ends, are 

 covered by layers of fat which vary in thickness, and are a rough 

 index of the condition of the animal. We note also that the fat 

 covering the trapezius muscle is invariably thinner than that 

 on the outside of the latissimus dorsi, and that in lean stores 

 the trapezius, especially in its upper or dorsal part, is hardly 

 covered at all. We note also that the other muscles (e.g. the 

 ilio-spinalis or the muscle forming what butchers sometimes 

 call the "eye" of the joint), which go to make up the meat, 

 are separated from one another by fascia and connective tissue 

 together with fat which like the superficial fat varies in amount 

 according to the beast's condition. This fat, together with that 

 referred to above as covering the outside of the joint, we speak 

 of as the "gross fat." 



Secondly, we generally see a certain amount of fatty tissue 



