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^ 130 EIGHTEENTH ANNHAL KEPORT OF THE 



l)ees, if they show the sj^mptoras of the disease, rarely are suffering 

 from it, and usually if they have a fair show they clean it up entirely 

 without aid. 



The second point is, the disease is prevalent in the spring and 

 earlj^ summer. Now that is a thing which we have all known to be 

 true for a long time, and we have had no adqeuate explanation of it, 

 but it is probably due mainly to the fact that at that time of the year 

 the colonies are not as strong as they are later on in the average apiary, 

 although that cannot be held to be universally true, because we do 

 sometimes get cases of European foul brood later, and we sometimes 

 get, as I say, colonies of bees that are strong which show the symptoms 

 of the disease. However, in an example of all the samples which have 

 come to our bureau during the last twelve years we find that they are 

 very predominant in June and drop off very rapidly after that. 



The third point is that the disease disappears in the summer, 

 unless the colony has become w^eak that they cannot throw it off. 

 That is also borne out by the figures from the samples received at the 

 bureau, and is borne out also clearly by the experience of the bee- 

 keeper. The disappearance of the disease usually accompanies the 

 beginning of the good hone.y flow. That is, whenever the time comes 

 in the season of the year when the honey flow is heavy, that is the time 

 for the disappearance of this disease. 



In 1899 Mr. N. D. West, one of the apiary inspectors of New York, 

 mentioned in an article in Gleanings — the first good article on this 

 that has appeared in America — a fact which has been overlooked 

 since. That is. he said that the earliest brood of the year usualty 

 escapes with a little loss. That fundamental thing in European foul 

 brood treatment has i)een overlooked in our literature, and I hunted 

 high and low through colonies I know of in New York and other places, 

 and while a great many people have known that to be true, Mr. West 

 pointed it out in 1899 and it has hardly appeared in the literature 

 since. 



We found out in connection with our European foul brood the 

 fact that some bees can resist this disease better than others, and 

 usually we see that the Italian bees can resist the disease better than 

 an\' other, and of all of the races that we have, I suppose that we must 

 give credit to this race for being the most resistant. 



Now, of course we know that it is an infectious rlisease ])ecause 

 it is always accompanied by bacillus pluton, as F mentioned a while 

 ago. It has never !)een found without this organism, and can be 

 ]^roduced artificially by treating this organism, so that it gives us a 

 clear case of infectious cause. 



Now, the disease differs from American foul ])rood very markedly 

 in the character of the bacteria which are present in it. Our old friend 

 American foul brood is caused by an organism which Ave call bacillus 

 larvae. Now bacillus larvae, when it runs out of food, that is, when the 

 larvae on which it is feeding are used up, forms a spore, extremely 

 resistant to heat and chemical disinfectants of all kinds, with the 

 result that we have there a form of life which is tremendously resistant 

 and hard to kill. For example, you can take American foul brood 

 and boil it for ten minutes at the temperature of boiling water, and it 



