4 



tion of the bees. The appearance of fungous growths was only a secondary 

 matter. 



Sohonfeld (22) infected several hives with foul brood and when it had 

 fully developed he took a comb of the rotten brood to the Physiological Insti- 

 tute at Brealau, and had it submitted to a microscopical examination by Drs. 

 Oohn and Eidam (22). This examination showed that in every dead larva, 

 and in each foul broody cell, whether the contents were yet white and fluid or 

 brown, tenacious and ropy, there were to be found long oval bodies, which 

 Preuss called " micrococci." " Close to and among them, Cohn was the first 

 " to find, with the most powerful of the five microscopes that were used, a 

 " countless number of slender pale rods, joined together, and which he at once 

 " identified as bacteria of the genus bacillus. The length of a single rod was 

 " about 6 micromillimetres, but many of them were two and three jointed, so 

 " that these foul brood bacteria microscopically resembled the anthrax bacteria, 

 " though of course they were diflferent physiologically and in the manner in 

 " which they acted as ferments." 



It is not surprising when we remember the state of bacteriological know- 

 ledge in 1870, that Preuss should have mistaken micrococci for the spores of 

 a bacillus In 1885, Cheshire & W. Oheyne (23) confirmed Cohn's conclu- 

 sions and demonstrated that the ditiease, foul brood, was caused by a bacillus 

 to which they gave the name of Bacillus alvei ; and they worked out the fol- 

 lowing requirements of the causal relation of this bacillus to the disease, 

 usually spoken of as Koch's rules : 



1 . Constant association of this germ (B. alvei) with the disease in the- 

 larvae of bees. 



2. Isolation of the germ from the diseased larvae, and study of the same 

 in pure cultures on various media. 



3. Production of the characteristic symptoms of the disease by inocula- 

 tion of pure cultures. 



4. Discovery of the same germ in the re infected larvae. Eeisolation 

 and growth on various media, comparable to that previously isolated. 



The infection brought about by Cheshire was accomplished by spraying- 

 a particular part of the comb with a culture of B. alvei in milk. This part 

 and no other became aflfected with foul brood. Adult bees were also infected 

 by feeding them with these cultivated bacilli. The experiments of Cheshire 

 and Chfeyne convinced everyone, and since that date B. alvei has been gener- 

 ally regarded as the causal agent in the production of this disease. 



Diokel (24) wrote in 1888 that several species of bacilli were able to 

 produce foul brood. There was one form of the disease which affected the- 

 unsealed brood, and another which affected the sealed brood ; and even a 

 third, a mixed form, which seemed to be most malignant. 



Elamann (25) supported Dickel's researches, but stated that it was not 

 necessary to count more than two kinds of the disease, as there were oprtainly 

 several other microbes which contributed to the ruin of the hive. Klamann 

 stated that he found seven and was persuaded that he would be able to isolate 

 an even greater number of bacteria from the diseased larvae. It seemed to 

 him certain that B. alvei was the wost virulent, and that this germ alone 

 was to be considered the cause of foul brood. 



Symptoms of the Disease. 



The disease principally affects the larvae. In a healthy comb the young 

 larvae lie at the bottom of the cells, curled up in the shape of the letter C and 

 in color ara of a pure pearly whiteness, plump in appearance, with full 



