CARTILAGE. 95 



to the enlargement of the fat drops, preserves its original 

 granular appearance. The nucleus is always visible, but, con- 

 comitantly with the increase of the oil drop, and the expansion 

 of the surface of the protoplasmic layer, is constantly pressed 

 outwards. In the final stages of development the remains of 

 the original investment of protoplasm consist only of a thin 

 homogeneous membrane, on some part of which the nucleus, 

 now become somewhat more homogeneous and diminished in 

 size, may always be demonstrated. The nucleus is best seen in 

 cells treated with Miiller's fluid, and then stained with carmine. 



If we institute a comparison between the fat cells in various 

 stages of their development, it becomes immediately apparent 

 that the protoplasm originally present does not merely ex- 

 pand coincidently with the enlargement of the cells, but that as 

 the cell attains its full growth, and becomes invested with the 

 above-mentioned membrane, the protoplasm also augments in 

 quantity. 



We possess no information from direct observation, of the 

 relation in which the protoplasm of the cell and the contained 

 oil stand to one another in regard to their nutrition. 



It is, however, certain, that wherever a new formation of 

 adipose tissue occurs, a supply of histogenetic substance in the 

 form of young cells first occurs, which is followed by a supply 

 of material for the growth of these cells. 



In consequence of hunger and disease, the fat cells lose their 

 oil, and become filled with a serous fluid. In rabbits, Cza- 

 jewicz* has observed the fat to disappear during abstinence 

 from food in the course of a few days, and with equal rapidity, 

 when abundant nutriment was supplied, reappear in the 

 original cells. 



CARTILAGE. 



Of this tissue those organs of the animal body are formed 

 either wholly or partially, which have long been noted in 

 anatomy on account of the persistence of their morphological 

 characters and great pliability, or from their peculiar consist- 

 ence when cut. In histology, the distinction formerly made 



* Reichert and Du Bois' Archiv, 1866, p. 289. 



