MUSCLE DEGENERATION IN AMPHIBIA 81 



mander the mj^ofibrillae, instead of forming sarcolytes, break up 

 into fragments at short intervals in their course, thus obUterating 

 the cross-striations and giving the affected part of a muscle fiber 

 a granular appearance. These fragments or granules fade away 

 as if by liquefaction. Their dissolution does not take place uni- 

 formly along the course of a fiber, so that in the extent of a well 

 advanced degenerating fiber indefinitely outlined groups of dis- 

 membered fibrillae can be seen. Coincidently with the lique- 

 faction of the fibrillae appear numerous spherical granules that 

 stain intensely with eosin, the eosinophile granules, which are 

 taken up by the leucocytes in the manner described above. Ac- 

 cording to Barfurth, in the frog larvae degeneration begins at 

 one end and gradually advances to the opposite end of the fiber. 

 While this is the case in some of the degenerating fibers in Sala- 

 inandra atra, it is not so with all, for in some fibers can be seen a 

 large gap, produced by degeneration, and containing numerous 

 eosinophile granules and leucocytes, while the ends of the fibers 

 appear quite normal. The sarcolemma degenerates simultane- 

 ously with the fibrillae. There are no evidences indicating that it 

 spans the gap of a degenerated portion of a fiber, which would be 

 the case if it were more resistant to the agencies bringing about 

 the liquefaction of the fibrillae. The muscle nuclei and sarco- 

 plasm are not transformed into phagocytes as is the case, accord- 

 ing to Metchnikoff, in larval frogs. No perceptible increase in 

 the amount of protoplasm or in the number of nuclei was noticeable. 

 They are, however, very resistant to the agencies that cause the 

 liquefaction of the fibrillae. During the last stages of degenera- 

 tion they can be seen lying free among the numerous leucocytes 

 and debris of degenerated muscle. On account of their large size 

 they cannot be mistaken for lymphocytes or for connective tissue 

 cells. Their fonn varies. Some retain their natural rod shape, 

 some are crescent in outline, some are bent double so that the two 

 ends are in close approximation, while others are bent and twisted. 

 A considerable number show marked signs of degeneration by the 

 massing of their chromatin. Their fate is unknown to me but 

 from the appearance of some I am of the opinion that they undergo 

 degeneration. 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 15, NO. 1 



