20 TATTY DEaENERATION. 



§ 26. This definition applies in the first instance to a meta- 

 morphosis of CELLS, which is characterised by the appearance of 

 oil globules in their interior, and which has therefore been called 



FATTY DEGENERATION. 



There was a time when men disputed whether the dark- 

 bordered droplets of oil, white by reflected light and soluble in 

 ether, originated in the cell contents, or in the nucleus, or even 

 in the nucleolus. At the present day, though no one would think 

 of denying the possibility of a fatty degeneration of the nucleus, 

 or of its nucleolus when present, and though Ave must assume 

 that in every case of complete fatty metamorphosis of a cell both 

 its nucleus and nucleolus are destroyed, yet it is universally 

 acknowledged that the disturbance invariably begins in the pro- 

 toplasm, and in the case of cells with a limitary membrane, in 

 the cell contents. The protoplasm, which normally exhibits a 

 very finely granular appearance, contains at first but a limited 

 number of oil globules, little groups of from two to ten being 

 usually seen in the immediate neighbourhood of the nucleus. 

 These globules never unite to form larger drops, a phenomenon 

 which is constantly exhibited by such particles of oily matter as 

 have penetrated into the cell from without (see below, fatty infil- 

 tration) ; they remain isolated from one another by thin layers 

 of protoplasm. The more numerous they become the narroAver 

 grows the outermost zone of the cell, which is still free from 

 them ; at length this vanishes, and the oil globules reach the 

 border of the cell. At the same time the nucleus, which had 

 hitherto been recognisable as a bright spot amid the dark mass 

 of oil globules, and which could be rendered evident by colora- 

 tion with carmine, ceases to be visible (compare with this and 

 the following sections, fig. 4). 



§ 27. During the occurrence of these changes the cell has 

 increased often to three or four times its former size ; it has, 

 moreover, become perfectly spherical, and this, whatever may 

 have been its previous shape, whether cylindrical, squamous, or 

 fusiform. It is now known as a " granule-cell," * and this term 



* The term " granule-cell " is decidedly preferable to the older ex- 

 pression " inflammatory corpuscle." Gluge, who found these corpuscles 

 in the lung at the outset of pneumonic infiltration, regarded them as 



