8 
production, and the use of high grade prolific 
queens render the colony practically immune 
to attack, or if carried out when infection is 
observed in its initial stages eliminate the 
disease. 
PREVENTION OF THE DISEASE. 
The method of prevention of attack by the disease, 
and of elimination of the complaint, is pointed out by these 
experiments, and the problem now resolves itself into the 
adoption of Rational methods of bee-keeping. 
By the avoidance of the inbred and degenerate 
British Blacks and strains containing a considerable pro- 
portion of this blood, by the use of exceptionally prolific 
queens of vigorous American—lItalian strains and by 
stimulation for brood production before and after the 
resting season of the year, the chance of infection is re- 
duced to a minimum. As the robbing of stocks infected 
by the parasite is the chief immediate cause of infection, 
this should be prevented at all costs, by isolation of the 
diseased colonies, and by reducing the entrances as much 
as possible in spring and autumn. As the parasite can 
only exist in the trachea of the living bee, and dies within 
a very short time of the death of the host, no danger need 
be feared from Acarine disease when old combs from stocks 
which have died from the complaint are utilised—provided 
the combs are allowed to remain out of contact with bees 
for a fortnight. There is also no danger of infection as 
the result of robbery of hives which have perished from 
the disease some time previously. 
ELIMINATION OF THE COMPLAINT. 
By the use of a microscope it is a comparatively 
simple matter to detect the disease in the initial stages of 
infection, some weeks before the usual symptoms of 
Acarine disease are visible, and when discovered at this 
stage it is usually possible to eliminate the complaint 
during the working season. To make plain the rationale 
of the process it is necessary to explain the course of the 
disease within the trachea of an infected bee. Experiments 
carried out during the investigation referred to previously 
have shewn, that young bees emerging from brood in an 
