14 MEETING OF [NSPECTOBS OF APIARIES. 



linn which is followed by a slow digestion or Liquefaction of the 

 casein; Bacillus larva does not grow in milk. In litmus milk. 

 Bacillus coli communis produces ;i large amounj of acid, which is 

 indicated by the change of the litmus to the red color: Bacillus alvei 

 produces no marked change in reaction, and Bacillus larva does 

 not grow in this medium. In the bouillons to which the sugars, 

 glucose, lactose, saccharose, etc., have been added, there is produced 

 by the growth of Bacillus coli communis, gas, and a large amount of 

 acid: Bacillus alvei doe- not produce gas and only a small amount 

 of acid by it- growth in the media containing sugars, while Bacillus 

 larva doe- not grow when planted in these " -oil-."* (I shall 

 speak later of a medium upon which Bacillus larva will grow.) 

 It is by these differences which we observe in the growth upon the 

 various media and the idled produced upon the different media by 

 the growth of the bacteria that we are able to determine one species 

 of bacteria from another. 



THE RESULTS OF THE ACTIVITY OF BACTERIA. 



Iii the consideration of this question it is convenient to divide the 

 bacterial flora into two groups — nonpathogenic, or those which do not 

 produce disease, and pathogenic, or those which do produce disease. 

 Some of th'* nonpathogenic bacteria are economically very important 

 as scavengers. The bodies of dead animals and plants are largely 

 brought to decay by them. The flavors of butter, cheese, and wine- 

 are thought to be improved by the growth of bacteria or other micro- 

 organisms — the fungi and the yeasts. Others of these micro-organ- 

 isms ruin the food, causing the souring of milk, the spoiling of fruit, 

 etc. Many diseases in man and animals are known to be caused by 

 bacteria, as tuberculosis, diphtheria, glanders, and anthrax. 



I wish now to speak briefly of how bacteriology has been used in 

 i hr study of bee diseases, and to summarize the results which have 

 been obtained. For a more detailed account you are referred to a 

 bulletin issued by the Bureau of Entomology of the United States 

 Department of Agriculture — Technical Series, No. 11. " The Bacteria 

 of the Apiary, with Special Reference to Bee Diseases," issued 

 November 6, L906. 



From what has been said one would naturally infer that in every 

 apiary, whether diseased or not, there are on the hives, comb-, and 

 bees a large number of bacteria that are perfectly harmless. If one 

 is trying to find in a diseased apiary the species of bacteria which i- 

 the probable cause of the trouble, what i- the method of procedure? 

 Suppose there were two herd- oi' cattle on adjoining farm- and the 

 cattle oil one farm were dying while those on the other remained well. 

 [f it were suspected that some plant which the cattle were eating wa- the 



