PLATE 7 



EXPLANATION OF FIGURES 



38 and 34 White bone marrow from a younger full-grown, well-fed chicken 

 in tissue culture at 38°C. from February 29 to March 1, 1916. Foot's 'Riesen- 

 zellen' already present after one day's incubation. 



35, 36 and 37 An identical piece of bone-marrow, as described above, was ex- 

 tracted after three hours and transplanted in a new culture medium. The next 

 morning, again extracted and transferred in a new medium. After eight hours 

 the preparation was conserved and the cells nearest to the network studied. 

 A cell, 35, of this preparation having migrated from the network, showing 

 phagocytosis. 



38 A cell of the network which begins to become disconnected. 



39 to 42 White bone marrow from a full-grown chicken in tissue culture from 

 February 22 to March 2, 1916, at 38°C. Regressive changes of cells of the large 

 mononuclear type or the myeolocytic type. 



The cells figured on figures 33 to 38 were conserved with Orth's fluid, those on 

 figures 38 to 42 with Schaudinn Sublimat Alcohol and stained with Giemsa 

 stain. 



120 



