4 The Lymphocyte and Lymphocytic Tissue 



wished to spend time investigating methods of staining these antolyzed re- 

 mains for the degradation products of nucleic acid.) 



I did not concern myself with the stainable Korper of reticulum cells in my 

 previous studies not because they were not interesting but rather because I 

 felt I had seen morphologic evidence that seemingly nonphagocytic reticular 

 cells rounded up to produce blast forms. My illustrations attest the difficulty 

 I had, for our undifferentiated reticular cell (Fig. 7 in Reference 13) from the 

 lymph node of a rabbit does contain phagocytosed lysed material in its cyto- 

 plasm (upper left corner, Fig. 7 in Reference 13) and one of my later cells 



■r 



»Jfc 



* * 









,*- 



Fig. l-l. Section of germinal center of hyperplastic lymph node. 

 Note reticular cells with stainable bodies. Note also numerous 

 mitotic figures. (X 440) 



(human lymph nodes) (Fig. 2 in Reference 8) was admittedly a "potential 

 phagocyte." Even the undifferentiated reticular cell shows an intracyto- 

 plasmic, oval, white inclusion (vacuole?) in the pseudopod-like process 

 extending to the right from the nucleus (Fig. I in Reference 8). 



With Trowell's hypothesis in mind, I have reviewed some of the material 

 I used in the previous studies 8 ' 13 and have confirmed the fact that morpho- 

 logically there does appear to be a complete series of lymphocyte-eating and 

 lymphocyte-digesting cells; the last cells of the series may show a remarkable 

 resemblance to cells I believe to be capable of functioning as precursors of 

 lymphocytes (hematopoietic reticular cells and reticular lymphocytes). This 

 series of cells is illustrated in Figures l-l through 1-8. 



