S4 RHODA ERDMANN 



are pictured in figures 11 to 26 are cells which have emigrated 

 early from the bone-marrow particle, advanced to the border 

 of the plasma medium, and changed in different ways. 



Figin-es 11 to 19 show the regressive development of the poly- 

 morphonuclear leucocyte which is inserted in the plasma, either 

 as a younger form, with spherical nucleus, or as an older form 

 with kidney — or horseshoe-shaped, or lobulated nucleus always 

 recognizable because of its acidophil granules. The long chains 

 of these deformed cells in all transitions are easy to identify in 

 preparations, where only a few cell types have been allowed to 

 emigrate into the plasma. Here they never take on the char- 

 acter of the 'cell culture type' (Foot). 



When bone marrow is taken from a young, poorly fed chicken 

 and treated as above described, few ' mononucleare basophile 

 Zellen' emigrate in the first half hour, and the bulk are only 

 eosinophil leucocytes (fig. 43). If these preparations are allowed 

 to develop two or three days the rays of cells consist for the most 

 part of these eosinophil leucocytes and few X cells or forms of the 

 cell culture type are visible. If the process of extracting and 

 again implanting the bone-marrow particle is repeated and the 

 cells of the succeeding emigrations are controlled, few eosinophil 

 leucocytes are observed in the second and third stage and after 

 the third implantation approximately no eosinophil leucocytes 

 are to be seen. 



Therefore, no new formation of this cell type from a stem cell 

 could be observed in the plasma clot, but only a process of 

 emigration, multiplication, transformation and degeneration of 

 those forms which were implanted with the bone marrow in the 

 plasma clot. 



THE FATE OF THE ERYTHROCYTES AND THE ERYTHROBLASTS IN 

 THE BONE MARROW TN TISSUE CULTURE ^ 



The general rule for the behavior of cells in tissue culture: 

 the more they are differentiated, or adapted to certain functions, 



^Erdmann, Rh. 1917 Some observations concerning chicken bone marrow 

 in living cultures, Proceedings of the Society for Experimental Biology and 

 Medicine, vol. 14, pp. 109-112. 



