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Acanthia lectularia 
almost invisible. Their condition cannot be foretold from the closest 
inspection of the living insect. The power of the smell bears a distinct 
relation to the size of the gland, being very strong when glands are well 
developed, and almost imperceptible when they are small. On one or 
two occasions the writer had mature specimens in which the glands 
could not be seen, and with them there was absolutely no smell, although 
all were dissected under the same conditions, and the writer’s olfactory 
sense was as acute as usual. Not only do they vary in size but also 
in appearance, being smooth in surface when full, and very wrinkled 
when partially empty. The evil-smelling contents of these sacs are 
described by Landois as an “ oily volatile fluid.” What may be its 
nature the writer cannot say, but it does not seem to be an oil. When 
the sacs are ruptured under water there is no trace of an oily film on 
the surface, and the water gives the same sort of “ jerk ” as occurs when 
a drop of spirit is allowed to fall on its surface. As Landois says, when 
the dissection is made in alcohol the smell is far worse. When weak, 
the smell produced by the bug has been described as the smell of old 
dirty clothes. How the bug profits by the great strength of its well- 
known stench has yet to be discovered. If the authorities can be relied 
on, cockroaches eat them with gusto, and have seriously been suggested 
as a means of ridding premises of them, so that evidently the smell is 
no protection from enemies. Perhaps the principle, prevalent even 
to-day, that the more nauseous a medicine the more efficacious it is, 
was what induced Dioscorides to give nine bed bugs enclosed in a bean 
as a cure for fever ; while Pliny gave an infusion of the bodies of seven 
crushed bugs to arouse from impending coma. 
The only good word ever spoken of the bug seems to be another 
remark of Pliny’s that hens that have eaten one will not that day die 
from adder bite. 
The odour is possibly of use to the bug when mating, and in the 
ordinary affairs of life it probably helps the social intercourse of the 
species in the gloomy recesses where they spend their lives, and in which, 
without a guide of some sort, they might have difficulty in finding 
each other. When kept in a close box they do not scatter themselves 
over its surface, but are always found gathered together in a solid mass, 
and this although the whole inside is equally dark and equally warm. 
Sex and physical condition of the bug as regards nourishment, 
seem to have no effect on the size of the glands, as they have been 
found large and small in male and female, whether full-fed or famished. 
There would appear to be some evidence to show that cold reduces the 
