PRESENT STATUS OF HSTESTIGATIOH OF BEE DI8EASE8. . r ) ] 



lure and the A r> (' of Bee Culture, coupled with the excellent repu 

 tat ion of Mr. Cowan, made this appear convincing i<> A.merican bee 

 keepers. It must l>e remembered, however, that at that time no one 

 had questioned the presence of Bacillus alvei in American foul 

 brood and on finding bacilli the conclusion that they were Bacillus 

 alvi i was natural, even though erroneous. 



Mi-. Edward Bertrand, in his book " Conduite dn Rucher," 1 makes 

 a similar announcement, stating that he and Mr. Cowan examined 

 brood described ;b ropy and found Bacillus alvei. 



[Mr. Dadant: I have received a letter from Mr. Bertrand. lie 

 informs me that they (Mr. Cowan and himself) had examined foul 

 brood, but I know from the tone of the letter that no cultures were 

 made. | 



To indicate how much reliance may In* placed in microscopic exami- 

 nations in the absence of cultural tests, let me quote from Sternberg's 

 Text-book of Bacteriology, L901 edition, pages L3 and II. It should 

 be home in mind that this refers to all microscopic examinations of 

 bacteria and not specifically to bee diseases. 



The bacteria are also classified according to their biological characters, ami it 

 will he necessary to consider tin 1 various modes of grouping them from different 

 points of view other than that which relates to their form. This is the more 

 important, inasmuch as we are not able to differentiate species by morphological 

 characters alone. Tims, for example, there arc among the spherical bacteria, 

 or micrococci, numerous well-estahlished species which the most expert micro 

 scopist could not differentiate by the use of the microscope alone; the same is 

 true of the rod-shaped bacteria. The assumption often made by investigators 

 who are not sufficiently impressed with this fact, that two micro-organisms from 

 different sources, or even from the same source, are the same because stained 

 preparations examined under the microscope look alike, has led to serious errors 

 and to much confusion. As an example of what is meant, we may refer to the 

 pus organisms. Before the introduction of Koch's "plate method" micrococci 

 had been observed in the pus of acute abscesses. Some of these were grouped in 

 chains streptococci and some were single, or in pairs, or in groups of four; 



hut whether these were simply different modes of grouping in ;i single species, or 

 whether the Chain micrococci represented ;i distinct -pedes. \\;is no1 determined 

 with certainty. That there were in fact four or more distinct species to he 

 found in the pus of acute abscesses was not suspected until Rosenbacb and 

 Passef demonstrated that this is the case, and showed thai not only is the 

 streptococcus ;i distinct species, hnt that among i he cocci not associated in 

 chains there are three species which are to Pe distinguished from each other by 

 their color when grown on the surface of a solid culture medium. One of these 



has n milk-white color, one is of ;i lemon-yellow color, while the third is ;i 



golden-yellow. 



This brings us down to the work of Doctor White. His investiga- 

 tions were begun with Dr. V. A. Moore in L902, and in January, L903, 

 a preliminary repoii was published. During the first year speci- 

 mens of "black brood" were examined and to the surprise of the 

 investigators Bacillus alvei was Pound in every case. Obviously, 



