HO VERA DANCHAKOFF AND S. M. SEIDLIN. 



found in the midst of the injected mass, are manifesting evident 

 signs of degeneration. A chromatolysis is frequently observed 

 in their nuclei at an early stage and later on these cells, even while 

 containing in their cytoplasm edestin granules, are themselves 

 subject to phagocytosis by other cells. 



By far the most important role in the actual digestion of the 

 injected mass belongs to those cells which are brought in by the 

 blood stream in the form of small lymphocytes. We do not mean 

 to say that the small lymphocytes as such devour a great amount 

 of edestin and digest it. But there is no doubt that cells, the 

 structure of which is identical to that of the small lymphocytes, 

 emigrate from the blood vessels, approach the injected mass and, 

 while approaching it, promptly change their morphological fea- 

 tures. Such cells, lymphoid phagocytes as we will call them, if in 

 contact with the injected mass of edestin, are seen, at the stage 

 of six hours after injection, to contain edestin particles in their 

 cytoplasm. The surface of their cytoplasm becomes indented and 

 tiny cytoplasmic processes are seen to protrude between the in- 

 jected edestin particles, to entirely surround them, to incorporate 

 them into larger vacuoles and to repeat the same process again 

 and again. Sometimes larger groups of edestin particles are 

 seen to be surrounded simultaneously by larger cytoplasmic proc- 

 esses and incorporated into a common vacuole. 



A greater and greater number of cells invade the edestin mass 

 until a stage is reached, about 24 hours after injection, in which 

 all of the edestin granules are found within the cells. At this 

 time (Fig. 2) the conditions within the injected mass are difficult 

 to analyze. The finest celloidin sections give rather obscure pic- 

 tures. All the edestin granules are found in larger or smaller 

 spaces surrounded by cytoplasmic strands, but the boundaries of 

 the individual cells are indistinct. Cytoplasm, a little more abun- 

 dant around the nucleus and easily recognizable as a part of a 

 definite cell, is seen to merge gradually into cytoplasmic strands 

 of neighboring cells. The whole region appears in the form of 

 vast plasmodia, here and there interrupted by more or less definite 

 fissures (Fig. 2). 



Figure 3 shows the development of these conditions in the 

 peripheral part of the injected mass. A vessel containing ery- 



