72 HISTORICAL NOTES ON BEE DISEASES. 



received labeled " black brood " were in most instances very probably 

 the so-called pickled brood. 



This completes for the present the consideration of the investiga- 

 tions made by Dr. Burri. His work is executed with much care, and 

 his results are correspondingly valuable. For this reason we feel that 

 anything which he writes on bee diseases can be recommended to the 

 bee keepers for careful study. 



Maassen, June, 1906. 



Several interesting papers on bee diseases have been written by 

 Maassen, of Dahlam, Germany. The first paper ^ to be considered 

 is on "foul brood." 



Of the samples received from 119 apiaries, 112 were found upon 

 exammation to be diseased. Of these 112 samples which were 

 declared diseased, Bacillus alvei was found in only 13. 



Maassen fed colonies large amounts of cultures of Bacillus alvei in 

 both the vegetative and spore form during the brood-rearing season 

 without producing the disease. An attempt was also made to inocu- 

 late the brood directly, but negative results were obtained by tliis 

 method (p. 59). The conclusion was therefore drauTi that Bacillus 

 alvei had not the significance in brood infection that had ordinarily 

 been attributed to it. In all cases where Bacillus alvei was not 

 found there were other spore-bearing species observed. The pres- 

 ence of one species is especially emphasized wliich offered much diffi- 

 culty in cultivation on the usual media of the laboratory (p. 60). 

 This species he refers to as Bacillus hrandenhurgiensis. No definite 

 proof was obtained of a causal relation between this spore-bearing 

 species and the disease. 



It seemed to Maassen at tliis time that spore-bearing bacteria were 

 probably only secondary invaders in tliis disease condition. He was 

 strengthened in liis belief by the finding of what he supposed was a 

 protozoan to wliich he gave the name Spiroclisete apis. In all brood 

 affected with the disease he records the presence of tliis micro- 

 structure. It was yet to be determined, he says, whether this last 

 finding bore any causal relation to the disease in which it was found. 



In this paper by Maassen the following points are of special 

 interest : 



1. Maassen was examining samples of brood which were suspected 

 by the bee keepers to be "foul brood." 



2. He does not mention two forms of "foul brood." 



3. He found Bacillus alvei in 13 samples of "foul brood" out of 

 112 samples diseased. 



1 Maassen, Dr. Albert, June, 1906. Faulbnitseuche der Bienen. Mittellungen aus der kaiserlichen 

 biologischen Anstalt f ilr Land- und Forstvrirtschaft. Heft 2, pp. 28-29. 



