38 Dr. Beck, Pathological Evolution. [May 27, 



of casual relationships for some forms of pneumonia and malarious 

 fevers. 



Now I do not positively say that this casual relationship exists, but 

 if so, and if all three are, as we have every reason to believe they are, 

 germ diseases, then we may fairly assume that my Worcester cases 

 were a practical indication of the possibility of germ transmutation. 



In other words, the conclusion is suggested that germs bred under 

 certain related conditions, finding dissimilar circumstances in different 

 subjects, might be assumed to possess the potential power to develope 

 in different directions, and cause in different individuals different 

 results. 



This is a wild speculation, it may be said, and so perhaps it is. 

 Facts, however, are facts, and from the facts I have above adduced, 

 my deduction is, I maintain, rendered probable. At least, it will be 

 conceded that there may be truth in it, and if true, a very different 

 realisation of the relationships existing between disease phenomena, 

 hitherto regarded as having no relationships, will be opened up. 



I maintain that with the advantages of this country for clinical 

 study, questions of this sort are of a kind which ought to come up, and 

 if some thought be induced in the direction I have indicated, I shall 

 not have come forward with my theories, crudely developed as they 

 are, in vain. The whole subject is full of practical application, and it 

 would require more time than I can give, or than it would be right to 

 expect you to give, if I were to enter fully into this aspect of the 

 matter. I may, however, briefly be allowed to show by a single 

 illustration the kind of application possible. To pursue this matter 

 exhaustively is not necessary. 



All medical men in practice will have come across many cases which, 

 as they go on, change their type. 



For instance, in the course of an ordinary pneumonia, a typhoid 

 condition supervenes, or in the course of an ordinary fever a sudden 

 pneumonia developes, and perhaps carries off the patient. How 

 perfectly explainable this becomes when we assume the possibility of 

 a change in the organisation of the germ which constituted the original 

 infecting factor. For various reasons, the pabulum in the body at the 

 time of infection preferred by one germ may become modified, or may 

 become exhausted. 



One of two results must follow, either the germ must die or 

 develope an aptitude for changed circumstances of life. This in so 

 low an organism as Pasteur has shown does not occur without some 

 change in its character, and change in character creates modified 

 result. As I have said, the subject is full of practical application, 

 and I venture to predict that in this direction lies the greatest 

 possiblity and probability for future pathological advance. 



It would be out of place for me to burden my communication with 

 an enumeration of clinical observations. I must not forget that I am 

 addressing a mixed audience, whose indulgence I may tempt too much. 

 To some extent I could not avoid doing this, however, and I may be 

 allowed to express a hope that the slight technicalities adduced may 

 not have been without sufficient general interest to justify them. 



It will be noticed that I have in my remarks touched upon the 

 ''evolution hypothesis" only in as far as it bears upon the external 

 agencies in disease. 



I have left untouched its application as regards the internal mechan- 



