82 J. A. BADERTSCHER 



The origin of the lymphocytes found in a muscle during its first 

 stages of degeneration can be attributed to two sources, namely, 

 connective tissue cells and the blood. The connective tissue cells 

 in the affected part of a muscle lose their stellate form, become 

 rounded, their nuclei grow denser, thus acquiring all the appear- 

 ances of nongranular leucocytes. This process is much like the 

 transfonnation into lymphocytes of the mesenchymal cells which 

 surround the epithelial anlage of the thymus in Axolotol as de- 

 scribed by Maxunow ('12). Metchnikoff ('84) also holds that in 

 Triton larvae transformed connective tissue cells assume phago- 

 cytic functions. It is difficult to determine to just what extent 

 the formation of lymphocytes takes place in muscle. However, 

 I am confident that the connective tissue cells do not transform 

 rapidly enough to account for the large numbers of lymphocytes 

 present. No mitotic figures were seen and only an occasional 

 dumbbell-shaped nucleus suggested amitosis. It is, therefore, 

 necessary to assume that the blood also is a source of a part of the 

 lymphocytes. According to an hypothesis of Metchnikoff ('84) 

 the endothelial walls of the blood capillaries are acted upon chemi- 

 cally, rendering them more permeable to leucocytes and permit- 

 ting of a 'passive diapedesis' of the red blood cells. Although 

 this is only an hypothesis, it seems to be a very reasonable way to 

 account for the presence of such large numbers of leucocytes and 

 also of red blood cells which are scattered in small numbers 

 among them, as was stated above. Since muscle degeneration in 

 Salamandra atra is an aphagocytic process it seems probable that 

 the cells of the delicate endothelial walls of capillaries may be 

 among the first elements to be affected. Another view, however, 

 may be taken. Dantschakoff ('08), in her work on the develop- 

 ment of the blood in birds, gives evidence that the cells of the vas- 

 cular endothelium have the power of transforming into lympho- 

 cytes. This genetic relationship of the leucocytes to the vascular 

 endothelium has also been held by other investigators. If this 

 view be correct, is it not probable that the vascular endothelial 

 cells- are transformed into leucocytes? This process also would 

 permit leucocytes and erythrocytes to escape into the intercellular 

 spaces. 



