THE PHILIPPINE 



Journal of Science 



B. Medical Sciences 



Vol. Ill APRIL, 1908 No. 2 



THE INFLUENCE OF SYMBIOSIS UPON THE PATHO- 

 GENICITY OF MICROORGANISMS 1 (THE 

 EVOLUTION OF PARASITISM). 



By W. E. Musgkave. 

 (From the Biological Laboratory, Bureau of Science.) 



contents. 

 Introduction. 

 Bacterial Symbiosis. 

 Animal and Bacterial Symbiosis. 

 Conclusions. 



, introduction. 



Symbiosis may be defined as representing all phases of association 

 between living organisms, beginning with commensalism on the one hand 

 and including true parasitism on the other, in which either component 

 is influenced in nutrition, metabolism, production, or in some other 

 manner by the presence of the other. Expressed in this broader sense, 

 the subject should be one of interest and its study and the elucidation 

 of its problems one of far-reaching practical importance. 



There can be no reasonable doubt but that the symbiotic combinations 

 between microorganisms are responsible for many uninterpreted phe- 

 nomena in the etiology and pathology of disease, and failure properly to 

 appreciate the existence of these combinations has been one cause of lack 

 of progress in serum therapy. When one. studies the rather meager and 



1 The President's Address, read at the Fifth Annual Meeting of the Philippine 

 Islands Medical Association, February 26, 1908. 



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