MUSCLE DEGENERATION IN AMPHIBIA 



71 



Among some of the muscles that undergo degeneration in this 

 salamander are the gill muscles, some of the muscles of the lower 

 jaw (fig. 1) and some of the dorsal muscles along the spinal column 

 (fig. 4). In the specimens studied, muscle degeneration was most 

 pronounced in those far along in their period of transformation or 

 in the young adult, thus indicating that even after the external 

 signs of metamorphosis have been obliterated, there are still mor- 

 phological changes taking place internally. In the degenerating 



Fig. 1 Part of a transverse section through the head of a 51 mm. young adult, 

 showing the position in the lower jaw of a muscle well advanced in degeneration. 

 M.c, Meckel's cartilage; d.ni., degenerating muscle; t., tongue. Photo. X 30. 



muscles and gills there is also a degeneration of blood capillaries. 

 As the capillaries are broken down there is a marked destruction 

 of erythrocytes which can be satisfactorily demonstrated espe- 

 cially in the degenerating gills. If the eosinophile granules are 

 derived from degenerating red cells and degenerating muscle tis- 

 sue, both granules and eosinophile leucocytes should be found in 

 connection with those tissues. On examining the different series 

 from the larval to the adult condition the evidence is conclusive 

 that the free eosinophile granules are products of the degenerating 



