156 CONNECTIVE TISSUE. 



the plastidules may, by a retrograde metamorphosis, be reestab- 

 lished in their original structure. * 



The fat-tissue met with in other varieties of connective tis- 

 sue, chiefly the fibrous, consists of a number of fat-globules, 

 aggregated into groups, which are termed fat-lobules. Such 

 formations are seen, in greatly varying amount, in the subcuta- 

 neous tissue, the female breast, the omentum, and around the 

 heart and the kidneys. The lobules being freely supplied with 

 capillary blood-vessels, besides these contain only a small amount 

 of a delicate fibrous connective tissue between the fat-globules. 



Fat-globules, which vary greatly in size, are inclosed by a 

 delicate continuous layer, termed the capsule of the globule. In 

 this capsule there is almost invariably found an oblong, nucleus- 

 like body, which in edge view appears to be fusiform, and blends 

 with the capsule. The fat substance proper contained in the 

 capsule is semi-fluid, and can be pressed out on artificially ruptur- 

 ing the capsule. Alcohol renders the fat coarsely granular, and 

 causes it to shrink. Chromic acid solution, after a certain length 

 of time, produces vacuoles in the fat-globule. Turpentine and 

 oil of cloves dissolve the fat, and the nucleated capsule becomes 

 plainly visible after the application of these re-agents. 



In fat-globules preserved for a period of several months 

 in a one-half per cent, solution of chromic acid, J. A. Rockwell, 

 in my laboratory, discovered bioplasson masses in the middle of 

 the fat. These masses, as a rule, appear coarsely granular with 

 lower powers of the microscope, often branch, and sometimes 

 contain a central nucleus-like body. High amplifications show 

 that the granules and the nucleus are interconnected by means 

 of delicate filaments. It also occurs that the bioplasson forma- 

 tion is flattened out near the capsule, or its granules are scattered 

 at greater distances through a portion of the fat. Small globules 

 contain one such granular formation, while large globules may 

 hold two 6r more in addition to a varying number of scattered 



* According to L. Ranvier ("Des Lesions du Tissu Cellulaire lache dans 

 PCEdeme," Comptes Rendus, 1871), in oedema produced by ligation of the vena 

 cava and discision of one sciatic nerve of dogs, the connective tissue infil- 

 trated with serum, twenty-four hours after the beginning of the oedema, 

 shows cells, the peripheral protoplasma of which contains granules of a fatty 

 appearance. Their refracting power is lower than that of fat, but if treated 

 with a weak solution of chromic acid or bichromate of potassa, they become 

 more highly refracting and smaller. These peripheral granules seem to be 

 composed, he says, of fat and an albuminous substance, just as in the devel- 

 oping fat-cells. 



