336 HISTOLOGY OF THE MORBID PROCESSES. 



that killed in the anaemic infarct. Such a replacement does not 

 take place in the kidney, but a scar of fibrous tissue is formed 

 around or in place of the necrosed mass. The karyokinetic figures, 

 then, simply demonstrate a tendency toward cell-division, and fur- 

 ther observations are necessary in order to determine the significance 

 of that tendency. 



1. Epithelium. The regenerations of which epithelium is capable 

 are very extensive and perfect. In some forms of epithelium 

 e. g.j the stratified variety and that found in sebaceous glands 

 the regenerative process is a part of the functional activity of the 

 tissue. After wounds of the skin the epithelium forming the epi- 

 dermis regenerates a new epidermis for the injured area. In this 

 case the epithelial layer, provided the wound be extensive, is rela- 

 tively thin and of low vitality. This is not because the epithelial 

 regeneration was imperfect, but because the nourishment it receives 

 from the underlying cicatricial tissue is deficient. There is in this 

 case a lack of coordinate development in the regenerations effected 

 by the epithelium and underlying fibrous tissues. Remarkable ex- 

 amples of a more perfect coordination are exhibited in the regen- 

 eration of glands (Figs. 297, 298, and 299), where the regenerating 

 epithelium and fibrous tissues appear to cooperate in the restitution 

 of lost glandular structures. 



The complicated glandular structure of the liver is also capable 

 of regeneration when a portion of that organ has been removed 

 under aseptic precautions (Fig. 300). Where, however, the de- 

 struction is due to damage exciting acute inflammation it is doubt- 

 ful whether any regeneration is possible, owing either to the inju- 

 rious action upon the cells, or to the hindrances interposed by the 

 regenerating portions of fibrous tissue in the neighborhood. 



2. Endothelium. That endothelium is capable of regeneration is 

 shown by the formation of young bloodvessels during the develop- 

 ment of granulation-tissue (Figs. 270 and 271). 



3. Fibrous Tissue. A mode of regeneration of this tissue has been 

 described in the article on inflammation, and is illustrated in Figs. 

 269 and 270. This tissue, when fully developed, differs from nor- 

 mal fibrous tissue in its density and freedom from bloodvessels (Fig. 

 273). The regeneration of a tendon severed under aseptic precautions 

 results in a much more perfect restitution of the normal structures. 

 Here the cut ends of the fibre show softening, swelling, and final 

 disintegration of the intercellular substance. Some of the cells are 



