76 HISTORICAL NOTES ON BEE DISEASES. 
Burri observed to be difficult of cultivation. As this species was not 
obtained in pure culture, no inoculation experiments were made with 
it. By feeding foul-brood material to ten colonies, however, Erne 
proved that the disease with which he was working was infectious, 
since in every case typical foul brood was produced which contained 
the same bacillus-previously observed. 
To make clear his position, Erne summarizes as follows: 
1. Burri has not furnished proof that sour brood is a contagious disease and that the 
bacterium described by him is the cause of the same. 
2. It is not proven that there is more than one foul brood germ. 
3. I consider as the cause of the epidemic foul brood causing the greatest destruction 
at the present time, a bacillus which I have found in all of my investigations, which 
can not be cultivated on the usual media, and which may perhaps be identical with the 
bacillus that Burri found to be difficult of cultivation. 
In Erne’s paper the following interesting facts are noted: 
1. He was working probably only with American foul brood. 
2. Erne took exception to the methods used by Burriin the attempt 
to obtain pure cultures of the bacillus which was found difficult of 
cultivation. 
3. He emphasizes the importance of the experimental inoculations 
of healthy colonies in the demonstration of the cause of a disease of 
bees. 
4. He did not find Bacillus alvei in 64 samples of foul brood exam- 
ined from Germany. 
5. He obtained negative results when healthy bees were fed pure 
cultures of Bacillus alvet. 
6. He questioned an etiological relation between Bacillus alvei and 
‘‘foul brood.” 
7. He demonstrated the infectiousness of foul-brood material by 
the production of ‘‘foul brood” in healthy colonies. 
8. He met with a species of bacterium in foul brood which was 
difficult to cultivate on artificial media. 
9. He considered this germ to be the cause of foul brood, although 
the fact was not demonstrated. 
10. Erne did not in his study of ‘‘foul-brood”’ material meet with 
a microorganism corresponding to Spirochete apis. 
While Erne does not devote much time to bee-disease investiga- 
tions, his writings show that considerable care is exercised in his work. 
The bee keepers, therefore, will be profited by reading any papers 
written by this author. 
Waitt, NOVEMBER 6, 1906. 
In 1906 the manuscript mentioned on page 67 was published as a 
bulletin. In the preface the reason for the selection of the names 
1 White, G. F., Ph.D. November 6, 1906. The bacteria of the apiary, with special reference to bee 
diseases. U.S. Department of Agriculture, Bureau of Entomology, Technical Series, No.14. Pp. 50. 
