86 HISTOBICAL NOTES ON BEE DISEASES. 



keepers to the important relation which exists between the etiology 

 of a disease and its rational treatment. 



The author at first deemed it advisable to direct the attention of 

 his hearers to a consideration of the nature of disease. A brief dis- 

 cussion is then given of the etiology of diseases, illustrating the state- 

 ments made mainly by citing phenomena observed in bee diseases. 

 In discussing the etiology, the usual division into predisposing and 

 exciting causes is made. Of the predisposing causes of diseases it 

 seemed well to mention age, sex, heredity, race, climate, and pre- 

 existing disease, inasmuch as these factors may be active in one or 

 more of the diseases of bees. Of the exciting causes of disease, food 

 and microorganisms are the only ones mentioned, since food, bacteria, 

 protozoa, and fungi have been thought by one writer or another to 

 be the direct exciting cause of bee diseases. A brief reference is 

 then made to the nature of bacteria, protozoa, and fungi. 



Mention is made in the paper of the fact that a microstructure had 

 been encountered m the investigations of European foul brood which 

 had failed to grow on artificial media. This was referred to ais 

 "Bacillus Y." Some hope was entertained that it might sometime 

 be proved to be the exciting cause of the disease. The great resistance 

 exhibited by the spores of Bacillus larvse toward disinfectants was 

 emphasized by citing some preliminary experiments. 



The following are some of the facts to which the attention of the 

 bee keepers was directed : 



1 . Disease is nothing more than a departure from a state of health. 



2. The departure is the result of some cause. 



3. The cause is, as a rule, a combination of factors which constitute 

 what is known as the etiology. Age, sex, race, and climate seem to 

 figure as predisposing factors in bee diseases. Bacteria, protozoa, 

 and fungi have all been studied as probable exciting causes. Bac- 

 teria are the only kind of a microorganism that has been proven to 

 be the cause of a bee disease. 



4. Comparatively little is known of the etiology of bee diseases — 

 a statement which, as one becomes familiar w4th the diseases of other 

 animals and man, is found to be true for them also. 



5. The exciting cause of but one bee disease is positively known. 



6. A rather interesting microstructure was encountered in Euro- 

 pean foul brood which had refused to grow when sown upon artifi- 

 cial media. This is referred to as '' Bacillus YJ' 



7. A treatment, either preventive or curative, can best be devised 

 only after the cause is determined. 



8. Before treating a disease, a diagnosis is advisable. This can 

 most accurately be done by knowing the cause and finding it in the 

 diseased body. 



