86 RHODA ERDMANN 



from young living erythroblasts and from young basophil cells 

 with vesicular nuclei are necessary, for deciding different ques- 

 tions. My experiments only proved, after isolating young cells 

 near to the bone-marrow network that they underwent no trans- 

 formation into erythroblasts but showed the phenomena fully 

 described later on page 94-100 the transformation into cells of 

 connective tissue cell type. It is naturally not excluded that 

 erythroblasts — when they are already erythroblasts in a strict 

 sense- — divide in the tissue cultures, but I never could isolate 

 this cell type with any certainty just at the point in being trans- 

 formed from its 'stem cell' into erythroblasts. This phenome- 

 non seems not to take place in tissue cultures. 



THE FATE OF THE IMPLANTED MICROLYMPHOCYTES IN TISSUE 

 CULTURES OF BONE MARROW 



The microlymphocytes in chicken bone marrow are found in 

 great quantities. Their small protoplasmic brim and condensed, 

 highly chromatic nuclei allow us to distinguish them easily 

 from the small basophile round cells "with vesicular and achro- 

 matic nuclei, closely situated to the network of the bone marrow. 

 The microlymphocytes seem to be present in the tissue cultures 

 from the first day of the incubation of the bone marrow, mthout 

 apparent changes, until the last day of cell life in the culture. 

 But are those the same forms which were incubated or newly 

 originated forms? The microlymphocytes implanted with the 

 bone marrow particle must be capable of active movements, 

 because they are no longer visible in the meshes of the bone 

 marrow network after several days' incubation, but are always 

 present in the plasma clot. In the preparations where only a 

 few cells are allowed to emigrate and to stay several days in the 

 plasma medium, the microlymphocytes are widely scattered. 

 Their own cytoplasm expands in a star-like manner, often 

 forming long cytoplasmatic raj^s. After a fortnight in the cul- 

 ture medium, they have the appearance of forms such as the 

 cells pictured in figure 25. One cell appears normal; the other 

 has a torn cytoplasmatic body. Figure 27 shows the remaining 

 nuclei which will soon undergo complete destruction. Foot 

 '13, page 43, believes that besides numerous microlymphocytes. 



