170 
NATURE NOTES 
650. “ The House Fly’s Record.” — Under the above head a terrible 
character has lately been given to the common house fly in one of the London 
daily papers. It is accused of carrying about dangerous bacilli on different parts 
of its body, and of spreading many diseases. 
I cannot help thinking this indictment is overdrawn. How does the house 
fly convey “typhoid, intestinal diseases,” and such like? Not by inoculation, 
for it does not bite us. Its proboscis ends in an enlarged sucker, which sips up 
sweets or liquids, and cannot pierce our skin or inject poison into our system 
like the gnats. The house fly is not to be confounded with a fly that is of the 
same size, and only too common, and may be distinguished by a sharp-pointed 
proboscis that stands out straight from the head. It is this fly that bites us 
through our socks and torments our horses. This methinks is a possible culprit, 
and not the house fly, though it does not affect putrid matter. Why are the 
bacilli on the house fly injurious to human life, and not those in a drop of water? 
That “public tips” are its “permanent breeding places” is non-proven. 
We do read that its larvae are to be found in manure and refuse of different 
kinds. Is even this really true? Has a house fly ever been seen to lay an egg 
on anything putrid or otherwise ? I doubt if any living entomologist can give us 
its life history from personal experience. If he can, let him produce some 
specimens which he has bred. 
South-acre, Swaffham. Edmund Thos. Daubeny. 
651. Moth Semhling. — During a recent lecture by a well-known naturalist 
the subject of “ moth sembling” was mentioned, and a description given of how 
the lecturer, in the course of a walk in the New Forest with a recently emerged 
female emperor moth in a cage, was beset by a large number of males of the 
species which had in some way become acrjuainted with the locality of the 
female. Observing that the wings of the female were in a constant state of 
vibration, the lecturer suggested that the information was conveyed to others of 
the species by means of these vibrations transmitted by the air. 
Whilst admitting the possibility in this case, I remember, some time since, 
placing a recently emerged female vapourer moth in an open tray on a window- 
sill about 30 ft. from the ground, and in the course of an hour not less than 
twenty males were seen fluttering upwards towards the tray, which some of them 
eventually reached with considerable difficulty, owing to the strength of an 
adverse wind. As the female vapourer moth is wingless, it is clear that the 
information as to its whereabouts could not have been conveyed by impulses 
emanating from wing vibrations, and as the males all came up against the 
wind it seems more probable that this curious kind of wireless telegraphy is 
brought about by the diffusion of some odour too subtle for perception by human 
olfactory nerves. 
The vibrations which are understood by us as perfumes are probably of shorter 
wave-lengths than those of light, our own appreciation of them, as in the case of 
sound and light, being limited within a certain compass ; but it seems highly 
probable that vibrations of much greater frequency than we are capable of 
perceiving may be readily appreciated by the delicate antennae of insects, 
specially attuned to vibrate in sympathy with them. R. T. Lewis. 
652. Spiders. — In No. 620 the opinion is held that “spiders can, but do 
not, bite human beings.” It is easy to put this to the test. If a good-sized 
spider be held between the finger and thumb so that it can bring its jaws into 
play, it will at once attempt to bite, but has not sufficient power to pierce the 
skin. If, however, any one cares to hold a large garden spider between the lips, 
the effect would probably be different and a little startling. 
Edmund Thos. Daubeny. 
653. The Rain Tree of Queensland.— Amongst the last parcel of 
produce received at the City Office of the Queensland Government, 73, Basing- 
hall .Street, are some pods of the “Rain Tree” {Pithecolobium Savian), an 
importation into the Colony from Peru. It is a valuable shade tree in tropical 
pastures. The name of “Rain Tree” is given because so great is the volume 
of distillation of moisture that the ground is wet under its branches. The cicada 
(a creature which buzzes amongst the branches of trees all day long) sucks the 
juice of the young branches and leaves and “ sejuirts forth slender streams of 
limpid fluid,” as an old naturalist writer has it. The pods in question are sent 
from Port Douglas, North Queensland. 
