312 



Messrs. W. Cramer and H. Pringle. [Jan. 25, 



fraction must remain constant if the animal is to live, and since it will be 

 increased rather by the presence of the tumour, which throws an extra strain 

 on the organism of the host. The tumour cells must therefore obtain their 

 nitrogen either from the growth fraction or from the ergogenic fraction. 



In the first case, we would have to assume that the cells of the tumour 

 have a higher aifmity for nutritive material than the growing cells of the 

 host, and that they withdraw some of the nitrogenous material which other- 

 wise should have gone to the building up of new tissues of the host. One 

 would then expect the growth of the host to be retarded, and there should 

 be a gradual diminution in the amount of nitrogen retained by the host. 



If, on the other liand, the tumour cells derive their nitrogen from the 

 ergogenic fraction, it would be unnecessary to assume any difference between 

 the affinity of the tumour cells for nutritive material and that of the growing 

 cells of the host. We would have to conceive that, after the wear and tear 

 of the organism of the host is replaced the growing cells, be they those of the 

 host or those of the tumour, have a first call upon the remainder of the 

 nitrogen, and that only the nitrogen which remains after their demands have 

 been satisfied goes to furnish energy. In other words, there would be a 

 sparing of the protein undergoing combustion in the organism of the host. 

 In this case one would expect to find the retention of nitrogen by the host to 

 remain constant and its weiglit to increase, while the nitrogen excretion in the 

 tirine would gradually diminish. 



Table IV gives the nitrogen retention per diem in three different periods. 

 The first pei'iod f)f the nine days before transplantation represents the normal 

 condition. The second period of the first nine days after transplantation 



Table IV. 



Nit.rof^cn-ivtcutioii of liost. during difTereiit. periods. 





Kat I. 



Kat II. 



Eat III. 



Period. 



Total ill 

 grammes. 



Per diem 

 ill 



grammes. 



Total in 

 grammes. 



Per diem 

 in 



grammes. 



Total in 

 grammes. 



Per diem 

 ill 



grammes. 



Before traiiBplnnta- 

 tiou (9 da^B) 



After 1 raiH])lanfca- 

 tioii, iBt period 

 (!) days) 



2nd period (0 days) 



0-37 

 0 -22 



Total ... 0-.'57 

 -Tumour 0 -12 

 Host ... 0-25 



0-04 

 0-02 



0-04 



0-72 

 0 -61 



Total ... 0-47 

 — Tumour 0 'O t 

 Host ... 0'43 



0-08 

 0-07 



0-07 



0-(?4 

 0-51 



0 ■;<r) 



No tumour 



0-07 

 0 -OSS 



0 -CMi 



