Histogenesis of the Adipose Tissue. 425 



adipose tissue were found. I have not examined the subcutaneous 

 fat-formation in any other part of the body. 



The manner of growth of adipose tissue in fattening will be taken 

 up later, but I wish to mention in this connection the development 

 of intramuscular adipose tissue. Fat cells are formed around the 

 blood vessels as in subcutaneous tissue, — the process extending out 

 on the smaller vessels as the animal fattens. Fat cells were noted 

 in the psoas muscles of a 51 cm. foetus and in several older specimens. 



The relation of the deposit of fat to the blood vessels. 



The earliest investigators of adipose tissue noted its great vas- 

 cularity. Flemming emphasized strongly the intimate relation of 



A ^S 



Text Figure 6. Two cells from the subcutaneous tissue of the brisket of a 

 24 cm. foetus. They He in the preadipose tissue near a blood vessel (Text 

 Fig. 1). f, spaces occupied by fat droplets; (j, Altmann granules; n, nucleus. 

 Fixation, Gilson's fluid. Iron-hiem. stain. X ^^^ 



the blood vessels to this tissue during development. The relation 

 of the blood vessels to the preadipose tissue of the renal region does 

 not impress me as being especially close ; but no one can fail to notice 

 such a close relation as shown in Text Figs. 1 and 4, where the 

 true adipose tissue is beginning to form. Equally impressive are 

 sections of the liver in many specimens. In several foetal livers the 

 cells adjacent to the veins were full of fat Avhen little or none was 

 found elsewhere (Fig. 1, Plate 1). In two young steers fat droplets 

 were found only in the cells adjacent to some of the medium sized 

 veins. When we compare the deposit of fat in the liver with its 

 first appearance in connective tissue there is seen to be a striking 



