DIGESTIVE ACTIVITY OF MESENCHYME. Ill 



throcytes and a number of small lymphocytes is found to be in 

 close apposition to it. A group of small lymphocytes in its prox- 

 imity are seen with large ameboid processes. At this stage most 

 of the edestin granules are incorporated in the cytoplasm of the 

 lymphoid phagocytes, only a few groups still remaining outside. 

 Most of them are situated in larger or smaller vacuoles. Appar- 

 ently one cell may possess a number of such vacuoles. Though in 

 general the cells appear to be well separated from one another, 

 there may also be observed groups of cells which seem to have 

 flown together. 



As early as 16-24 hours after injection a change takes place in 

 the numerical relation between the polymorphonuclear leucocytes 

 and the lymphoid phagocytes, now both appearing in the form 

 of large cells with vast vacuoles containing large amounts of 

 edestin granules. The polymorphonuclear leucocytes, even more 

 abundant than the lymphoid phagocytes early after the injection 

 become now scarce and rather difficult to identify. A granular 

 leucocyte, as admitted, is a highly specialized cell, stable and no 

 longer capable of developmental changes. Would such a cell 

 under experimental conditions be still capable of modifying its 

 metabolism so as to manifest a fundamental change in its struc- 

 ture? This idea, incompatible as it seems with our knowledge of 

 histogenesis of blood cells, is forced upon one's mind by the 

 rapidity of the change in the numerical relation of these two dif- 

 ferent kinds of phagocytes. And only a detailed analysis of the 

 conditions obtaining within the injected mass permits of a final 

 refutation of this idea. The polymorphonuclear leucocytes nu- 

 merous in early stages become less and less so, because of the 

 association of various factors all working in the same direction. 

 Soon after the first wave of emigration brings around the injected 

 mass a large group of polymorphonuclear leucocytes, lymphocytic 

 cells become more and more abundant within the blood stream and 

 are seen to emigrate in larger and larger numbers. At the same 

 time the polymorphonuclear leucocytes, well within the edestin 

 mass, begin to degenerate in great numbers. In later stages many 

 of them are seen to be ingested by the lymphoid phagocytes. As 



