AUTHOR 8 ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIBLIOGRAPHIC SERVICE. NOVEMBEK 7 



DIGESTIVE ACTIVITY OF MESENCHYME 



A. THE EHRLICH SARCOMA CELLS AS OBJECT 



VERA DANCHAKOFF 



Columbia University, George Crocker Special Research Fund, 

 F. C. Wood, Director 



EIGHT PLATES (SEVENTEEN FIGURES) 



1. STATEMENT OF THE PROBLEM 



Resistance to heteroplastic grafting is a property possessed 

 by a great variety of organisms. Even tumors with their un- 

 Hmited power of growth cannot be transplanted successfully 

 from one species to another, and transplantation to another 

 animal of the same species has often been followed only by par- 

 tial success. Among higher vertebrates an entire lack of resist- 

 ance to certain heterogeneous rapidly growing tumors has 

 been demonstrated in only a few instances. Murphy and Rous 

 grew different tumors on chick embryos. Bullock succeeded in 

 growing mouse sarcoma in new-born rats. 



Although various hypotheses as to the factors of resistance 

 have been formulated, none is actually fundamental, though 

 some are apparently well supported. Both organs and cells 

 have been suggested as factors responsible for natural as well as 

 induced resistance against the grafting of tumors. The spleen 

 among organs and the small lymphocytes among cells have been 

 made subjects of special study in this connection. Inhibition 

 of tumor growth due to the presence of the spleen in the organism 

 has been affirmed and denied, as has an inhibiting effect of the 

 splenic tissue on the growth of a tumor graft. On the other 

 hand, receding tumors are often infiltrated by small lymphocytes, 

 and it has been suggested that the presence of these cells may be 

 a factor in the recession. 



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