BIOLOGICAL MEASURES IN THE TREATMENT OF CANCER 235 



For the moment, the point that I would emphasize is that the 

 entire group of biological cancer remedies as above outlined com- 

 prises agents of very diversified origins that have at least one 

 prominent point of contact in the presence of organic proteins. 



If we add that among all the numberless agents that have been 

 used in the general treatment of cancer, there is not one at present 

 commanding the slightest scientific consideration that does not 

 contain protein, we are at least put in the way of an interesting 

 and suggestive line of thought. 



The ideas thus engendered are naturally linked with the reflec- 

 tion that many students of cancer have attempted to associate 

 the genesis of the disease with defects of protein assimilation; 

 and also with the very interesting studies of Bulkley in the treat- 

 ment of cancer by careful regulation of the diet with reference 

 to the protein intake. 



The full bearing of the observation, however, is appreciable 

 only when we reflect along the line of the now familiar physio- 

 logical principle that the introduction of a foreign protein paren- 

 terally leads to a development by the body of antibodies to 

 antagonize the toxic influence of that protein; and the further 

 reflection that the antibodies in question are produced by the 

 system in excess of the quantity required merely to neutralize 

 the foreign agent. 



A classical illustration of this is found in the use of the anti- 

 typhoid vaccine, which leads to the production of antibodies in 

 such excess as to give the individual immunity to the typhoid 

 virus for a term of months or years. 



A moment's further reflection shows that the antibodies thus 

 produced when a foreign protein is introduced in the body must 

 be of a character to effect the decompounding of the protein 

 molecule. If the thesis of the Proteomorphic theory is accepted, 

 it follows that the introduction of a foreign protein will result 

 in the increased activities of the white and red blood corpuscles 

 and of the organs that produce these corpuscles. Specifically, we 

 may expect that after introduction of a foreign protein there 

 will be observable a modification of the blood count in the 

 direction of an increase of large mononuclear lymphocytes and 

 red blood corpuscles. We may assume that there is a responsive 

 increase in the quantitative enzymic activities of these corpuscles, 

 and that the aggregate effect exceeds the immediate needs of the 

 system as induced by the invading protein. 



In other words, there will remain a residual quantity of en- 

 zymes in the blood capable of decompounding proteins. 



These residual enzymes obviously constitute an agent capable 

 of attacking other foreign proteins, unless we assume that they 



