2(uS 



By this method I somclimos succeeded in getlinj^ a micro- 

 scopical I'iehl with a vitally stained sarcoma cell in close 

 proximity to an unstained normal fibroblast. 



In thr nieanlinu' the results of these e\|)criments were 

 rnllier lu^atiw It was never learned by the method whether 

 a sarcoma cell was able to liarm a normal 

 til)r()l)last in a wa\ that could be observed 

 directly. I'xperimenls of this kind naturally 

 demand a patient observation over a lonj^ 

 [period of time. If nothing happens within 

 a relative short time, the vitally stained 

 sarcoma cells become decolorized and no 

 longer recognisable as sarcoma cells. 



An other exi)erimental device gave mucli 

 better information. 



A few carcoma cells were added, by 

 means of a pipette, to a big culture of fibro- 

 blasts grown in one of the culture flasks 

 (type D) ad modum Carrel *5'''). A few days 

 later it w^as observed that the plasma in 

 the periphery of the tissue l)egan to liquefy, 

 (Fig. 71). The zone of liciuefaction increa- 

 sed in size and the colony of fibroblasts 

 was found as a small retracted piece of 

 tissue on the shore of the lake of liquehed 

 plasma. At the end of three weeks or so. 

 the entire plasma in the c"ulture flask had 

 cells. Ttie figures hquefied. 



represent ttie vari It has been a generally opinion though 



ous degree of lique- „ot supported by experimental facts, that 

 ^'^ '*^" connective tissue cells are able to over- 



grow the malignant cells in cultures. We know, further- 

 more, that fibroblasts can hardly be avoided when other 

 kinds of tissue colls have to be obtained in pure culture. 

 l-"rom experiments undertaken here, it seems as if tlie 

 malignant cells are able to sujjpress the growth of hbro- 



Fig. 71. 

 A culture of fibro- 

 blasts contaminated 

 witti a few sarcoma 



