758 



VOLUNTARY MUSCLE. 



broken into larger and smaller shapeless clumps (Fig. 498), which may 

 disintegrate and finally be absorbed. Hand-in-hand with these changes 

 there usually occurs an increase in the iuterfibrillar connective tissue, 

 and in certain cases there may be a proliferation of the muscle nuclei 

 and a new formation of variously shaped cells within the sarcolemma 

 which leads to the regeneration of the fibres. As a result of the brittle- 

 ness of the degenerated muscles they are apt to rupture, and in this way 

 haemorrhage may occur. 



This form of degeneration may occur in progressive muscular atrophy, 

 in various infectious diseases, in trichinosis, with local inflammation, 

 injuries, freezing, etc. It is, however, most marked and frequent in 

 typhoid fever. In this disease the rectus abdominis and the abductors 

 of the thigh are most frequently affected. 



Experimental investigations have shown that, under certain condi- 

 tions, very similar appearances may be produced in the muscles by post- 

 mortem changes. Various changes some of them necrotic are at pres- 

 ent included under the name hyaline degeneration of the muscles. 



True amyloid degeneration is rare. 



Hoen has described a peculiar degeneration with atrophy of the stri- 

 ated muscle of the uvula, in which a series of bleb-like structures form 

 along the fibres, which they may finally replace. ' 



Calcification of muscle is of rare occurrence. 



Serous or Hydropic Infiltration of muscle fibres occurs under various 

 conditions in association with other lesions. Larger and smaller spaces 



FIG. 498. HYALINE DEGENERATION (SO-CALLED WAXY DEGENERATION) OF ABDOMINAL MUSCLE IN 

 TYPHOID FETEII. 



filled with clear fluid are present between the fibres and often over small 

 areas largely replacing them. Such fluid-filled spaces are often called 

 vacuoles. 



INJURIES, HEMORRHAGE, AND INFARCTION. 



Wounds and Rupture, When the muscle fibres are severed by wounds 

 or rupture there is more or less degeneration of the divided fibres, and 

 the wound may heal by the production of granulation tissue, which grad- 

 ually becomes converted into cicatricial tissue, thus binding the severed 

 parts together. In some cases there is a moderate new formation of 

 *Hoen, Jour. Exp. Med., vol. iii., p. 549, 1895. 



