220 DISEASES OF THE JOINTS. 



greater softness than ordinary, so that the cells can be pressed 

 out of it. 



" In the neighbourhood of the incisions into the cartilage of 

 the patella, and upon the trochlear surface of the femur, though 

 not extending upon the condyloid surfaces, the substance of 

 the superficial layers of the cartilage has become converted 

 into a membrane composed of granules, nuclei, and fibres. 

 The formation of this membrane may readily be traced by an 

 examination of it at the line of junction of the trochlear and 

 condyloid surfaces, where it becomes thin before it ceases to be 

 observed. The contents of the cells first become granular, and 

 the hyaline substance soft and more transparent ; the walls of 

 the cells disappear gradually, and scarcely anything but cell 

 membranes, granules, and molecules, lying in a hyaline mass, 

 can be seen ; fibres are then formed between the nuclei, and the 

 latter either disappear altogether or elongate into nuclear fibres, 

 and thus a dense fibrous mass is produced. If during this pro- 

 cess the cells have become larger than natural, they give to the 

 junction of the cartilage and membrane a notched appearance, 

 by bursting and discharging their contents into the latter ; but 

 if no enlargement has taken place, the textures run into each 

 other so insensibly that no distinct line of demarcation can be 

 drawn between them. 



" The portions of tlie texture through which incisions were 

 made present similar appearances in every instance. Not the 

 slightest difiiculty is experienced in making sections through 

 both the cut surfaces and the substance by which they are 

 firmly united. Such sections show the cut surfaces to be very 

 uneven, and hollowed into small pits of the size of the cartilage 

 cells of these parts. The pits are obviously produced by the 

 half-destroyed cells, the former contents of which are now seen 

 lying on the surface. No evident change has taken place in 

 the texture of the cartilage at a little distance from the cut 

 surfaces, except that here and there the intercellular substance 

 presents a fibrous appearance. There is no obvious enlarge- 

 ment of the cells, or crowding of their interior with corpuscles, 

 as is frequently seen to occur under similar circumstances. 

 The substance uniting the cut surfaces consists of a hyaline, 

 gxanular, and indistinctly striated mass, in which there are 

 numbers of rounded, oblong, elongating, or irregularly shaped 



