OUR KNOWLEDGE OF INSECT VECTORS OF DISEASE. 



Table VII. 



The more Important Insect-borne Diseases of Fungus Origin. 



it;:; 



Organism. 



Host. 



Disease. 



Vector. 



Achorion schonleinii 



Man 



Favus Lice {Pediculus).* 



Conclusion. 



It should be borne in mind that a large number of diseases included in the foregoing 

 Tables are not spread by insects alone, and insect transmission may in some cases 

 be only occasional. This fact, however, does not justify the exclusion of such 

 diseases from consideration, and where transmission of the indirect type is possible, 

 it is obvious that we are unable to form any just estimate of its relative importance. 

 Probably nevertheless the dissemination of pathogenic micro-organisms by flies, for 

 all that has lately been said in this connection, has not even yet been over- emphasised. 

 It seems more than likely that Bacillus tuberculosis is spread in this manner from 

 infective sputum to food (milk particularly) to a much greater extent than is com- 

 monly imagined, and there being no probability of rapid acute infection, as with 

 B. typhosus, the part played by the fly is too apt to be over-looked. 



Much of our knowledge with regard to insects and disease is still indefinite, as may 

 be seen from the Tables, but to anyone not particularly conversant with the subject, 

 what we already know with certainty, even in connection with only the more important 

 diseases that have been considered, may be sufficient to cause some little surprise. 



