28 POISONOUS PROTEINS 



Schultze's definition be changed to read: ''A 

 cell is a corpuscle of protoplasm which contains 

 a specialized element, nuclein." 



It should be understood that the cellular sub- 

 stance which I have been discussing is not iden- 

 tical with that which exists in the living, mul- 

 tiplying bacteria. The latter consists of the 

 former with the addition of all the extractives 

 which I have removed by the solvents, such as 

 water, dilute alcohol, absolute alcohol and ether. 

 The living bacillus has been stripped of all its 

 surrounding food supplies, its accumulated ex- 

 cretory products and its storehouse of fats, 

 waxes, etc. I have a strong suspicion that in 

 some of our bacterial reactions, notably with 

 precipitins and agglutinins, these extractives 

 are concerned, while the cellular constituents 

 have no direct part. The active constituents of 

 the culture, the agglutinable substance, is not, 

 in my opinion, an essential constituent of the 

 bacterial cells, but consists of one or more pro- 

 teins closely associated with the bacterial cells. 

 It may be a protein already split off from the 

 surrounding pabulum preparatory to absorp- 

 tion and assimilation, or it may be an excretory 

 product. My reasons may be stated as follows : 

 (1) Agglutination does not destroy the viabil- 

 ity or virulence of bacteria; therefore, the re- 



