DISEASES AND ENEMIES. 
567 
of its growth — sometimes the rods are longer and 
stouter than at others ; but its colony form is quite 
constant, and the spores, and the methods of their 
production, are always the same. In blood serum, 
this bacillus grows with even greater vigour than it 
does in the body of the bee. Variation, which will 
account for the disease being sometimes especially 
virulent, is commonly observed in micro-organisms, 
and forms the very basis of the system of attenua- 
tion for inoculation purposes as practised by Pasteur 
and others. Where the queen is diseased, probably 
no treatment will be efficacious until she has been 
replaced. This is a problem which seems to forbid 
solution, since we have no means of determining the 
condition of a queen until her life has been sacrificed. 
Those who believe that the replacement of the queen 
is all that is needed for a cure, will soon get evidence 
of their palpable error. Pricking a needle into a 
diseased larva, and then touching a larva in a healthy 
hive with it, is, five times out of six, enough to start 
a vigorous attack. It could not, however, be supposed 
that the queen is, in such a case, the cause of the 
malady. Summer is, without doubt, the best time for 
treatment, as then the bees can not only more easily 
bear the necessary disturbance and the chilling, but 
they can be aroused to rapid brood-raising, which 
involves the application of the remedy. 
Bags containing camphor, placed within an infected 
stock, have been stated to work a cure. They pro- 
bably are an advantage, and might be used in winter ; 
but, in my own trials. Bacillus alvei has gone on 
developing and extending its ravages, notwithstanding 
