Isle of Wight Disease in Hive Bees. 45 
the most certain evidence of the presence of Nosema apis is afforded by 
finding the characteristic spores. Unfortunately these are not always 
present. .. . Our observations show that during the warmer months the 
parasites often do not reach the spore stage, but seem to kill the affected 
bees before this stage is reached” (p. 48 of 1913 report). 
Our evidence is unfortunately rather contradictory, as we have been 
able to find abundance of spores in the months of May, June, July, August 
and September as readily as in other months. Our illustration of a section 
of a chyle-stomach in which every visible cell is heavily infected with 
spores (Pl. I. fig. 2) is from a summer bee. And we are a little doubtful 
of any heavy mortality resulting entirely from infection in the period of 
the bees’ maximum vigour, at an early stage of the parasites’ growth. This is 
especially so since we have found, throughout the summer, living bees 
without. any obvious signs of disease, which proved to be very heavily 
infected with spores. Further it is claimed that the chyle-stomach of the 
bee is, even under normal conditions, constantly shedding and renewing 
its secreting epithelium. 
PULPING EXPERIMENTS. 
The routine of examining individual bees for Nosema diagnosis, although 
valuable and most reliable as regards the single bee in question, has several 
serious disadvantages. The first of these is due to the amount of time 
required to examine thoroughly even one bee, and the second, which 
depends upon this fact, is that one is led to base conclusions regarding 
a whole stock upon the results obtained from the examination of relatively 
insignificant numbers. A small sample of bees taken at random from a 
stock does not correspond, say, to a sample of a homogeneous fluid or solid 
substance. 
This difficulty has been largely overcome in our later work by the 
introduction of the method of pulping collections of bees designed for 
examination for the presence of Nosema spores. Our method is simply to 
cut off the abdomens of the bees, letting them drop into an ordinary mortar. 
They are then gently pulped in sufficient water to render the contents fluid. 
Sometimes we have removed the alimentary canals from behind the honey 
sac and teased these collectively in a little water in a large watch-glass. 
Samples of the resulting fluid in either case are taken up with a pipette, and 
if Nosema spores are present in the pulped preparation, they are usually found 
in the first drop examined. Our first experiment of this nature was as 
follows. 
