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21
not claimed by CursurnE, and the belief is not grounded on bacte-
riological findings. »WnrrE himself did not succeed in finding any
bacteria in bees died from paralysis that produced the disease.
Suspicions that moulds may be the cause of the trouble have, how-
ever, been expressed in that country as seen from a communica-
tion in GLEANINGS OF BEE CULTURE (Barstow 4). The interesting
but rather vague ideas of the trouble are stated in the following
way: »When plenty of honey is coming in, the bees show no sign
of sickness, but later in the summer or fall the bees may get some
honey containing pollen that might be poisonous, or that has sour-
ed, or grown mouldy to a certain extent; so that when they feed
on it, it is in the right condition to cause what might be called
constipation.»
2. The toxicity of moulds to the honey-bee.
The bees used in the following feeding experiments were Italians
and ordinary black ones. They were kept in spacious boxes co-
vered with glass and wire gauze. The cages were placed in a
warm room (25°C—28°C) and darkened with paper. The fungous
material was mixed with honey, somewhat diluted with sterilized
water, and: given the bees in sterilized food cups covered with
gauze to prevent the insects from getting drowned. The boxes,
when used several times in different series, were repeatedly clean-
sed and flushed with boiling water. Two of the moulds used in
the experiments, Penicillium sp.’ and Penicillium stoloniferum Thom
were isolated from the intestines of dead bees, kindly supplied from
the Entomology Department, Experimentalfaltet. The others were
isolated from honey-combs. They were grown in slanted 150 x 30
mm. agar-agar tubes, the medium used being of the same composi-
tion as the one described in Turesson 24.
Penicillium sp.
Series I.
June 27. 16 bees were used. 0.5 grams of spores and mycelium
were mixed in 10 cubic centimetres of honey. The bees showed
sign of uneasiness already the same day, and frequently cleaned
* This species is probably new, and will be described in detail at another ocea
sion.
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