CHICKEN BONE MARROW IN PLASMA MEDIUM 81 



droplets. They belong to the so-called 'cell culture' type. 

 Besides these cells we find others with oblong nuclei and elon- 

 gated cytoplasmic bodies full of glistening fine granules. These 

 move slowly and show fine pseudopodia formed by their 

 delicately granulated cytoplasm. 



To summarize: Fat containing bone-marrow of chicken when 

 incubated for 9 days in a plasma medium, undergoes the fol- 

 lowing changes which can be observed in the living preparation: 

 The signet-like fat cell disappears, it is transformed to 'Riesen- 

 zellen' and finally to the 'cell culture' type. This type includes 

 round cells with coarsely granulated cytoplasm, big shining 

 droplets and oblong, less refractive nuclei. The other prevail- 

 ing cell-form is distinguished by its finel}^ granulated cytoplasm, 

 elongated or round cell body, and oblong nucleus. 



These two cell types (not widely different in their morpho- 

 logical bearing) are always to be found among the cells which 

 have migrated from the implanted bone-marrow particle into 

 the plasma clot. Besides these cell forms, — capable as it seems 

 of metabolism for long periods, — we see all forms of disinte- 

 grated cells. The cytoplasm and nucleus separate and the 

 preparation is filled with debris. Fat droplets of different 

 sizes which are freed from the cell fill the preparation. Nuclei 

 of small granulocytes and lymphocytes without cytoplasm are 

 often seen. Also shadows of blood corpuscles and granulocytes 

 of all sizes are present. 



It is certain that in non-renewed tissue culture retrogressive 

 and progressive processes take place. It will be necessary to 

 investigate the more intimate phenomena of these changes in 

 stained preparations specially adapted to the study of each dif- 

 ferent cell type by different methods of cultivating and staining. 



THE FATE OF THE MONONUCLEAR AND POLYMORPHONUCLEAR 



EOSINOPHIL LEUCOCYTES OF THE BONE MARROW IN 



TISSUE CULTURE 



While describing the changes of the living bone-marrow cells 

 after they had been 1, 24, 42, 72, 96, and 216 hours in the plasma 

 medium, — the present author could give little or no definite 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 22, NO. 1 



