2()() 



were either rather distinct, lig. 61,, or were only re- 

 presented as several ()ieces of chronuilic fra,i>nu'iits, scattered 

 in the prot()|)lasni. 



These kinds of cells were rather nnniei-oiisly re|)resenled 

 in ail the cultnres of llu' chicken sarcoma. Besides this 

 type, another cell type was represented, namely, a medinm 

 sized with a rather clear cytoplasm, very finely granulated 

 and containing a few vacuoles only. Fig. 65 " represents 

 this type. The movement of the cell was also vei'v lively. 

 The changes in the outline of the cell can be followed in 

 fig. 65; the tinu- it took for the cell to adapt the various 



Fig. 64. 



The type of ttie small cells in the Rous's 



sarcoma, stained with Azur 11. 



shapes, illustrated in fig. 65, was about 10 minutes. The 

 cell, representing the medium sized type of cell, could be 

 seen wandering in and among some other cells in the 

 same microscopic field. 



2. The lype of bU] ameboid cells. 



Characteristic for these cells is the slow movement of 

 their' cytoplasm. The shape is rather spherical and the 

 cytoj)lasm highly granulated and the nucleus can very seldom 

 be seen in the living cells, fig iUi. When stained, the nucleus 

 is rather distinct and usually contains one big nucleolus 

 and a couple of smaller ones, fig. 67. Very characteristic 

 is the peculiar way the granula and vacuoles are arranged. 

 Often big vacuoles are arranged as a single layer in the 

 periphery of the cell, or they are arranged as a circu- 



