THE EVOLUTION OF THE PROTEIN PRINCIPLE 239 



SECTION V 

 THE EVOLUTION OF THE PROTEIN PRINCIPLE 



Charles Darwin was accustomed to emphasize the value of 

 hypothesis as an aid to scientific discovery. This value is, indeed, 

 so evident that the statement of it is almost a truism. Yet it is 

 equally true that a false hypothesis may constitute one of the most 

 hampering of obstacles in the way of progress. 



I was forcibly reminded of this, when, a few weeks after the 

 issue of the first edition of the Monograph so frequently referred 

 to, I came upon a report that had hitherto escaped my attention, 

 in which an account was given of some very remarkable experi- 

 ments in the treatment of cancer in the human subject with an 

 alleged "X" substance said to be extracted from thymus of the 

 calf. The report appears in a volume issued by Columbia Uni- 

 versity Press in the year 1913 captioned "Studies In Cancer and 

 Allied Conditions," and said to be issued from the department of 

 zoology, surgery, clinical -pathology, and biological chemistry 

 under the auspices of the George Crocker Special Research Fund 

 at Columbia University. 



This is one of a series of volumes with which I had consider- 

 able familiarity, but I had failed to note the essential part of the 

 particular report in question; otherwise I should very eagerly 

 have welcomed it as giving support to a quite different theory 

 from the one that the authors of the investigations were pursuing. 



The report in question bears title "The Relation of Certain 

 Internal Secretions to Malignant Tumors." The investigation 

 was said to be conducted "with the idea of throwing some light 

 on the relation of some of the internal secretions to malignant 

 tumors." But in point of fact, the part of the report to which 

 I refer has, in my opinion, no essential relations to the subject 

 of internal secretions. The investigation was indeed conducted 

 with the aid of extracts made from the thymus gland ; but in my 

 opinion that fact was merely incidental, and precisely the same 

 results would -have been attained had the extracts been made from 

 any one of a score of other tissues of the animal body. 



In other words, in my opinion and indeed, in the light of new 

 evidence, I think it hardly open to doubt the observations made 

 had reference to the results of introducing foreign proteins into 

 the parenteral system, though the authors themselves make it 

 positively clear that they had no such conception. Probably they 

 will repudiate the suggestion now that it is made. Nevertheless 

 I believe the suggestion to be entirely valid. 



