213 



the melhod to Ihc cultivation of oilier tissues than nervous 

 fibres, and lo eonijji'ehend tissues from warm blooded ani- 

 mals, and attempts were made lo cultivate malignant tissue 

 cells in vitro The results of these experiments in general are 

 few, and have been rather disappointing to most invest- 

 igators. Most observations hitherto made on malignant tissue 

 cells in vitro, have not been able to give any biological 

 characteristics of these cells, which were not also found for 

 normal tissue cells. 



As early as in 1910 Carrel and Burrows 7'^) issued the 

 first reports about the cidlivation of malignant tumor cells 

 They succeeded quickly in cultivating the Rous chicken 

 sarcoma, the E h r 1 i c h and Jensen sarcoma of the rat, 

 a primary carcinoma of the breast of a dog ^6) ^^), and 

 two human tumors, a sarcoma of the fibula and a carcinoma 

 of the breast. Lambert and Hanes 3og) 307) 309) have culti- 

 vated rat and mouse sarcomata, and a mouse carcinoma. 



L o s e e and E b e 1 in g '''»^) have cultivated human sar- 

 comatous tissue in vitro. Recently Drew '^•'') has made a 

 comparative study of normal and malignant tissue cells in 

 vitro. His technique is that which only allows of a survival 

 of the cells and is not a culture according to Carrels 

 definition. 



As just stated, the malignant tumor cells in vitro have 

 not manifested themselves in any striking and characteristic 

 way. The only difference from that of normal tissue cells 

 is that it proved to be technically more difficult to culti- 

 vate malignant cells in vitro than was found to be the case 

 for normal tissue cells. So far, it has only now been man- 

 aged to overcome the technical difficulties for the cultivation 

 of the Rous chicken sarcoma indefinitely outside the body, 

 in the same way as is the case with that of fibroblasts, 

 epithelium, cartilage and lymphocytes. Probably other malig- 

 nant tissue cells from other animals and even the human 

 tumor cells may be cultivated in a similar wa}^ ^^^) -"3). 



16* 



