334 



HISTOLOGY OF THE MORBID PROCESSES. 



FIG. 296. 



Phagocytes from aseptic granulations. (Nikiforoff.) C, phagocytes with pseudopodia; E, 

 without pseudopodia ; F, proliferating, the daughter-nuclei in the spirem phase of karyo- 

 kinesis; A, B, D, with leucocytes, fragments of tissue, and red corpuscles in their cyto- 

 plasm. 



those in the blood and lymph ; l but it is possible that young con- 

 nective-tissue cells, which are believed to possess the power of arnos- 

 boid motion, may sometimes play the part of phagocytes. 



IV. REGENERATION OF THE TISSUES. 



Frequent reference has been made to the power possessed by 

 many cells to restore or regenerate structures that have been dam- 

 aged by influences causing either necrosis or degeneration. The 

 ability to effect this restoration varies greatly in the cells of different 

 tissues, being, in general, inversely proportional to the degree of 

 specialization to which they had attained at the time the damage 

 took place. We must, therefore, consider this process in the dif- 

 ferent tissues separately, after taking a general survey of the facts 

 that apply to all cases of regeneration. 



It is needless to say that a cell which has once become necrotic 

 is incapable of restoration ; but if the nucleus be sufficiently pre- 

 served and enough cytoplasm be left after degenerative changes 

 have come to an end, both those cellular constituents may take up 

 nourishment and regenerate the parts destroyed. When whole 

 masses of tissue have been killed, but some of the same form of 

 tissue retains life and continuity with the necrosed portion, the 

 dead tissue may be more or less completely replaced by tissue 



1 The polynuclear neutrophile leucocytes are those which most frequently act as 

 phagocytes. 



