340 



HISTOLOGY OF THE MORBID PROCESSES. 



partial degeneration the cytoplasm around the nuclei that have 

 been preserved may increase in amount, the nuclei may divide, and 

 a multinucleated cytoplasmic mass result from the union of these 

 rejuvenated portions. From this mass new contractile substance 

 is then elaborated. This process results in regeneration of the 

 particular fibre. It is still a question whether new striated muscle- 

 fibres are produced in consequence of regenerative processes follow- 

 ing damage. Wounds of voluntary muscles heal through the 

 formation of a cicatrix (Fig. 306). 



8. Cardiac Muscle. Karyokinetic figures have been observed in 

 the cells of the heart-muscle, but they do not appear to lead to re- 

 generation of that tissue, which heals with the production of scar- 

 tissue when wounded. 



9. The Nervous Tissues. Ganglion-cells have not been observed 

 to rejuvenate so as to produce fresh nerve-cells ; but if the cell -proc- 

 ess forming part of a nerve is severed from the cell without serious 

 damage to the cell-body, a new process or nerve-fibre is developed 



FIG. 307. 

 KS KZ KS 





Longitudinal section of a regenerating nerve. (Stroebe.) N, nerve; P, perineurium, con- 

 taining more cells than normally ; KZ, phagocytes, containing globules of myelin from 

 the medullary sheaths of degenerated fibres; K, nuclei of proliferated cells of the 

 neurilemma ; F, young axis-cylinders ; KS, points showing the relations of the nuclei 

 and young nerve-fibres ; B, bloodvessel in the perineurium. 



(Fig. 307). The cells of the neuroglia are, on the other hand, 

 capable of regenerating that tissue. In this respect the neuroglia 

 resembles the interstitial tissue of other organs than those of the 

 central nervous system, often increasing in amount when there is a 

 diminution in the bulk of the parenchyma, due to disease. 



