METHODS OF HEALING. 



479 



interesting, and a recently formed granulation, when examined 

 with the microscope, will be seen to be composed of numerous 

 cells heaped together without apparent arrangement, and con- 

 nected by very little intermediate substance (protoplasm). Some 

 are round, others caudate, spindle-shaped, elongated, or splitting 

 into fibres. Singly, they are colourless, but in clusters they are 

 ruddy — even independent of the blood-vessels. As the cells 

 become developed into fibres in the deep layers of the exudation, 

 the superficial ones, arrested in their development, become con- 

 verted into pus cells, which, after having served to protect the 

 deeper seated and more permanent ones, are thrown off in the 

 discharge. 





"^o, 





Fig. 108. — Vertical section of a granulating sore. Externally, pus 

 corpuscles ; deeper, fibre cells in various stages of development into 

 fibres. The looped blood-vessels are seen enlarged at their ex- 

 tremities. Magnified 100 diameters linear. On the left the cells are 

 magnified 200 diameters linear. — (Bennett.) 



The connective tissue thus constructed by the development 

 of the cells gradually assumes the characters of that tissue, and 

 as it becomes more consistent and dense, the discharge of pus 

 diminishes ; a new surface is produced, which after a time 

 contracts, and a permanent cicatrix is formed. After a time 

 yellow elastic tissue is developed, and becomes mingled with the 

 white fibres of the scar. 



Granulations are sometimes arrested in their development 

 from some unknown causes, as in indolent wounds and ulcers. 

 In these cases, as is sometimes seen on the legs and backs of 

 horses, months may pass and the cells will not develop them- 



