PRESENT STATUS OF INVESTIGATION OF BEE DISEASES. 47 
importance, for, as everyone knows, the disinfecting power of direct sunlight is 
much greater than diffused light, and the vitality of the spores from foul-brood 
masses of different ages varies considerably. This, I may add, has been clearly 
shown by some of my experiments, subsequently described. In my experiments 
the spores obtained from a pure culture on the surface of agar were spread on 
cover glasses and placed in a glass chamber, so arranged that a current of air 
was constantly circulating over them. This chamber was exposed to the ordi- 
‘nary light of a room with six large windows, and a cover glass was taken out 
every twenty-four hours and tested, to see if the spores would grow. This 
experiment was continued for one month, and at the end of that time the spores 
still germinated rapidly. In another experiment, spores spread on cover glasses 
were exposed to a very diffused light, simulating, as far as possible, the amount 
of light which would enter a hive. Cover glasses were taken out from time to 
time and transferred to agar, in order to ascertain if the spores were alive or 
not. The experiment was begun two years and four months ago, and from the 
last cover glass taken and placed upon the surface of an agar plate a copious 
and typical growth of B. alvei was obtained. Further, thin strips of filter 
paper, plunged into a bouillon culture and allowed to dry, were threaded on a 
wire suspended in a wire basket and so exposed that the air could freely cireu- 
late around them in the ordinary light of a room. Trial cultures were made at 
intervals, and at the expiration of six months the spores from the paper germi- 
nated when strips were placed on the surface of agar. 
Again, a drop of bouillon containing spores was placed in a sterile tube and 
allowed to Gry; and at the expiration of one hundred and twenty-four hours 
(thirty-six of which were in sunlight at a temperature varying from 30° to 
37° C.) sterile bouillon was added. The tubes were then placed in the incubator, 
and in less than twenty-four hours a good growth of the germs had taken place. 
From these experiments it will be seen that the results are directly at 
variance with Howard’s statement, as they go to show that the vitality of the 
spores of B. alvei is not destroyed by exposure to atmospheric air, with or 
without sunlight, for even a much longer time than twenty-four to thirty-six 
hours. 
With regard to the aerobiosis of this bacillus, good growth has been obtained 
in an atmosphere of hydrogen by Novy’s method. Buchner’s method also gave 
good results. The growths in the various media are very similar to those pro- 
duced under aerobic conditions, but with this difference, that the surface 
growths are, as a rule, whiter in the hydrogen atmosphere. In illuminating gas 
(water gas) no growth occurred, but the spores were not destroyed by the 
action of the gas; for when the gas was let out of the Novy jar, good growth 
ensued on all cultures. In acetylene gas, a restricted growth occurred. In 
fermentation tubes growth occurred both in the open and in the closed arm 
of the tubes. No gas was formed, the bouillon in the closed arm was uniformly 
turbid. Thus B. alvei is a facultative anaerobe. 
Production of alkalii—in ordinary bouillon a slight amount of ammonia is 
formed. Control bouillon did not give the Nessler test. In glycerine and the 
sugar bouillons, there is no trace of ammonia. Cheyne’s cultures are faintly 
alkaline, both before and after inoculation in meat infusion. Klamann states 
that ammonia is produced. 
Acids formed.—A varying amount of acid is formed. All the sugar bouillons 
give an acid reaction. 
Formation of pigment.—On potatoes a yellowish growth is produced; on all 
other media, the surface growth is white. 
Development of odors.—Cheyne states that gelatine cultures give off an 
