XATURAL HISTORY XOTES 
Head Hawk, in which case it has been suggested that the squeak may be of 
sexual importance as well as a means of defence. I admit, though, that some 
moths may emit sounds imperceptible to human ears. It is a well-known fact, 
however, that many moths have distinct odours, and these may or may not be 
the means of attraction. It has also been proved that the males perceive the 
scent of the females by means of their antenniu, because when the latter were cut 
off the presence of the females was unnoticed. Some of the most obviously 
attractive females are practically wingless, whilst others are provided with ample 
wings ; and in the latter class some are quite (piiescent, whilst in others the wings 
are in constant vibration. It has been thought that the vibration helps the diffusion 
of the scent, which is, perhaps, less volatile in these species. In some few cases 
it is the male which attracts the female, and then /le is the scented one. In the 
case of the ghost-moth the male is believed to attract the female partly by sight, 
whence his white colour, and partly by a distinct scent which he emits. Generally 
speaking, female moths are mosf attractive within twenty-four hours after they 
have emerged from the chrysalis. C. Micholson. 
678. House Fly. — There are still some points in the life-history of the 
House Fly to be cleared up. As no eggs, larvx, or pups have as yet been dis- 
covered in the winter, I am inclined to think that the race is carried on by those 
perfect insects which survive the dangers of hybernation. This supposition, how- 
ever, has its difficulties, and may be quite wrong. Shortly after the fly emerges 
from the pupa in summer or early’ autumn, pairing takes place, and a batch of 
from 120 to 140 eggs is laid ; and the question is, does the fly lay more than one 
batch ? IMany hybernaling insects, e.g., the Vanessida and Clouded Yellow 
Butterflies, do not pair before hybernation, and lay their only batch of eggs in 
the spring. Some bumble bees and wasps pair before the winter, and lay their 
eggs next spring. Certain beetles are said to pair more than once, and to lay 
several batches of eggs ; but do they do this before as well as after hybernation ? 
Edmund Thos. Daubeny. 
679. — What a delightfully caustic summary of man’s attitude towards far too 
many of the humbler creatures of this earth is contained in the brief extracts 
given by Mr. Daubeny (p. 212) from the Preliminary Report on the Habits, &c., 
of the House Fly in Liverpool ! After showing that this species performs a very 
great service for man, which his education is too imperfect and his laws too 
inadequate to ensure his performing for himself—to wit, the safe removal of 
a mass of pestilent matter — this report proceeds to stigmatize this highly valuable 
scavenger as a pesl, merely because it sometimes and in some few ways (in most 
cases easily preventable by him) annoys him or carries unpleasant and perhaps 
dangerous matter into his house, which — in ninety-nine cases out of a hundred — 
already reeks with a far greater quantity of deleterious matter than flies are ever 
likely to introduce. Perhaps the revelation of the house fly’s usefulness will 
induce “ the authorities ” to pause before they enter on its extermination ; a 
remedy which might prove much worse than the disease, as has been the case 
before, again and again, through man’s interference in cases of which he knew 
only one side. C. Nicholson. 
680. Magpie Moth and Euonymus.— In answer to the question 
asked in the review of “Nature Rambles in London ” (p. 173), I can testify that 
Abraxas grossulariala is very guilty of larval attacks on Euoitymus japonicus in 
some of the London suburbs. At Clapton their depredations are obvious. 
C. Nicholson. 
681. Balsam Poplars. — Is it possible that Mr. Taylor’s trees (p. 192 ) are 
infested with Goat-moth or Wood Leopard caterpillars, or other internal feeders? 
Clay soil is not likely to be the cause, I think. Holes in the trunks about J in. 
across would indicate the presence of the caterpillars. It is difficult to say 
definitely, without examination, what could be the cause of the trees dying. 
C. Nicholson. 
682. Spring Flowering of Erigeron acre. -There ought to be little 
difficulty in deciding whether the plants referred to by Margaret Baggallay 
(p.^172) are E. acre or E. alpinttm, seeing that the former is an annual or 
