2(i2 



lar laycM- around llu' very lincly jframilalcd mass of the 

 central j)art of llic ci'il fig. 67,.. At oIIut limes one will 

 see colonies of even-sized vacuoles, surrounded i).\ a Ihin 

 meml)rane somewhere in the cytoplasm, fig. ()7i. Sometimes 

 structures can be seen in the cytoplasm, which look almost 

 like crystals of fatty acids. 



.V. The type of spindle-shaped cells. 

 These cells look almost like ty|)ical fibrol)lasts. hut rather 

 big. Sometimes they resemble most of all the transition forms 

 between the big mononuclear ivmpliocyles and fil)roblasts. 



Fig. 66. 

 The type of big ameboid cells of ttie Rous's sarcome. 



which are described by Carrel '"0 i. e., the one end of the 

 cell is thin and filiform as in fibroblasts, and the other 

 end may show filiform or tongue-like j^seudojxxls. The 

 cytoplasm is usually filled with granules. The nucleus may 

 be found with a distinct membrane, containing one to four 

 nucleoli, fig. 68. Other cells of this type may show peculiar 

 chromatic fragments distributed in the cytoi)lasm. fig. 69. 

 CJiaracteristic for all the cell types from tlie sarcomatous 

 tissue is their great activity. Vixen the slow mo\ing cells 

 exhibit a greater motile activity than do the normal fibro- 

 blasts. Characteristic for the sarcoma cells is their ability 

 to unite and amalgamate with other similar cells. It seems 

 here to bi' a real imition which lakes |)lace. It is not 



