INFLAMMATION. 



119 



As the granulation tissue grows, new, small spheroidal cells are gath- 

 ering by proliferation or by continued emigration. Some of these par- 

 ticipate in the formation of the granulation tissue, while others, not find- 

 ing conditions suitable for their fur- 

 ther development, or even for their 

 continued existence, die and pass off 

 on the surface, together with some 

 transuded fluid, as pus. 



The polynuclear leucocytes do not 

 apparently share in the formation of 

 new tissue. Whether this is largely 

 or wholly derived from small spher- 

 oidal cells which may result from 

 proliferation of old connective-tissue 

 cells, or whether, as is now confi- 

 dently claimed by many observers, the emigrated lymphocytes, assum- 

 ing the characters of "plasma cells" (see page 103), may be also con- 

 cerned, is not yet certain. 



Cicatricial Tissue. The new tissue gradually becomes more and more 

 dense, the intercellular substance more abundant, while the cells decrease 

 in number and become flatter and less conspicuous. The epithelium may 

 now grow over from the sides, forming by mitosis from the old epithe- 

 lium at the edges of the wound (Fig. 49), and finally cover the new 

 vascular tissue. The new tissue, having at last undergone more or less 

 shrinkage, with atrophy of the blood-vessels, consists of a dense, firm 



FIG. 48. FIBROBLASTS OF NEW CONNECTIVE 

 TISSUE IN A HEALING WOUND. 



There are numerous new-formed intercellular 

 fibrils. 



FIG. 49. HEALING WOUND IN THE TONGUE OF A DOG. 



There was loss of substance muscle, flbrous tissue, and surface epithelium. The lost tissue has been 

 replaced by the vascular granulation tissue which is oldest and most dense in the deeper portions, while on 

 the surf ace is a layer of tissue detritus, pus cells, etc., partly dried, and forming a scab over the granulations. 

 New epithelium is pressing forward from the old at the edges over the surface of the new-formed tissue. 



mass composed largely of fibrillar basement substance with a few flat- 

 tened cells (Fig. 50) ; and with this, which is the cicatrix, the healing is 

 complete. 



Variations in the Healing Process. Although in the production of new 

 tissue in connection with or following exudative inflammation essen- 



