DISEASES AND ENEMIES. 
535 
reveals the presence of not only contagious or zymotic 
diseases, but occasionally curious organic disorders ; 
i.e.^ in the viscera of the large number of workers 1 
have examined, one ailment of the latter kind — a form 
of liver trouble — has occurred a considerable number 
of times, and in bees coming from many different 
localities. The Malpighian vessels (page 6i, Vol. I.) 
become loaded with, and surrounded by, a dark 
yellow-coloured oil, contained in cells, until the half, 
perhaps, of the abdominal cavity is filled. No practical 
purpose would be served in further describing the organic 
afflictions of the poor bee, or in detailing the physical 
deficiencies from which she occasionally suffers, such 
as defective eyes, imperfect sting, crumpled wings, 
or incomplete antennae, since neither the physician 
nor the surgeon is likely to devote his attention 
to individual cases. It is here sufficient to remark 
that these flaws arise either from a defect in the 
mother, or unfavourable conditions in the colony — 
too low a temperature, or a dearth of water, being 
the usual cause — although they are sometimes due, 
as we shall presently see, to the existence of a disease 
which is wasting the vitality of the general community. 
Especially is this true in that most curious occurrence 
of hermaphroditism, of which, hereafter, I will endea- 
vour to give the key. 
The contagious diseases of bees, unlike those that 
are functional or organic, frequently attack the larger 
number of individuals composing the colony, while 
the malady may travel with devastating effect from 
stock to stock, until the whole apiary is ruined. They 
are caused by the growth and rapid multiplication 
