310 



Messrs. W. Cramer and H. Pringle. 



[Jan. 25, 



If the malignant new growth secreted a substance of the nature of a toxin, 

 one would expect to find at least a diminished nitrogen retention, if not an 

 actual loss of nitrogen as the tumour increases in size. Our experiments 

 give no evidence of the presence of a substance having a disturbing action on 

 the nitrogenous metabolism. 



The nitrogen retained during the experiment must have been allotted 

 partly to the somatic tissue of the host on the one hand and partly to the 

 tumour on the other. The proportion of nitrogen which goes to build up the 

 new growth was found by determining the nitrogen contained in the whole 

 tumour. The results of the analyses of the tumours are given in Table II. 



Table II. 





Amount of 

 tumour used 

 for analysis 

 in grammes. 



Nitrogen found 

 in grammes. 



Total weight 

 of tumour 

 in grammes. 



Nitrogen in 

 total tumour 

 in grammes. 



Average nitrogen- 

 content of 

 total tumour 

 in grammes. 



Rjit I... 



1 -095 



0 -02.534 





0 -1180 











' 5 -10 





0-1220 





1-025 



0 -02534 





0 -1260 





Eat 11... 



0 -297 



0-0084 





0 -ou 











1 -.55 





0 -0435 





0-323 



0 -00896 





0 -043 





The proportion of N used to build up new somatic tissue can be found by 

 subtracting tlie N-coutent of the tumour from the nitrogen retention of the 

 host plm tumour. 



Table III gives the proportions of nitrogen which have gone to the building 

 up of the somatic tissue of tiie host and to the formation of tumour tissue 

 respectively. The results can be stated best in the form of tlie (luotient, 

 N-retention : Increase in weight. This quotient indicates the nitrogen value 

 of the unit of tumour tissue, and unit of somatic tissue of the liost 

 respectively. 



It is ol)vious that, before transplantation, the relation N-retcnl,ion to 

 increase in weight should he the same in the three rats, nud as a niiittiu- of 

 fact this was found to be the case. Since nuitabolism ex]Hn'imeuts on rats 

 have not often been made, we may point out here that the con.stancy of the 

 ligures obtained is evidence of the reliability of our observations. 



The nujst striking result obtained after tiaiisjiliuitation is the bict that tlits 

 quotient is smaller in the case of the new grow th than in the case of the 

 somatic tissue of the host. In other words, less nitrogen is needed to build 



