786 
Supplement to the "Tropical Agriculturist." [May 1, 190^. 
plants ; so we must try to save what moisture is 
already in the soil through previous rains. 
Q, How can we make soil moist or keep soil 
moist ? 
A. By surface tillage. It'keeps a soil moist 
by preventing it from drying out. When soil is 
left undisturbed for a long time, and becomes 
packed down, the moisiure in the soil works 
towards the surface and is evaporated, so passing 
off into the air. Tillage, or stirring the top layer, 
make a surface soil mulch through which the soil 
moisture cannot pass. It is really equivalent to 
covering the soil with a layer of straw or board. 
Every cultivator kuows how moist it is under a 
pile of straw which has remained in a place for 
some time, or under a board. The straw or board 
does not make the soil moist but prevents it 
from drying. This is what surface tillage does. 
THE ENTOMOLOGY OF THE HOUSE FLY. 
The house fly, like the poor, is always with u?, 
and it would be to the advantage of everyone to 
know all about so familiar an insect, and what 
its power for good and evil are. 
In tlie Agricultural Journal of Cape Colony 
Mr, Charles Loundsbiiry contributes, under the 
head of Eutomology, an interesting paper on " the 
house fly," containing a good deal of information 
which it is desirable we should add to our 
knowledge of human things'. 
Mr, Louudsbury gives us an instance of the 
ignorance prevailing on such a common subject. 
He says: I once met a man who was kindly 
disposed towards the house fly, who confessed to 
a fondness for its company akin to that felt for the 
trusting robin red-breast that comes to the 
door-step at home when snow covers the ground, 
who was not annoyed when an ovor-advesiturous 
fly dropped into >!)is coffee, and who never exerted 
him.self to destroy the busy ones which strove to 
share his sugar. His house was kept scrupulously 
clean, and flies consequently were not numerous 
therein, or he might perhaps have held diiferent 
views concerning these little buzzing guests. He 
told me he honoured the fly for its intelligence, 
for its extraordinary vision and the beauty of its 
complex eye structure, and, most of all, for its 
peculiar attachment to the habitations of man 
throughout the wide world. He seemed well 
acquainted with the creature as a fly and in the 
liouse, but, strange to say, he had never probed 
its earlier history or enquired into its out-door 
habits ; and his respect for the little insect seemed 
.so genuine and unaffected that I forbore from 
enlightening him. Ignorance to him was indeed 
bliss. And if any of my readers hold similar 
views, if they have any affection at all for the 
house fly and desire to retain it, they had best 
read no furtiier. My design in penning these 
notes is to malign the little pest, to lay bare its 
iniquity, to brand it an abomination of the vilest 
type, and to instil loathsomeness toward it. I 
liave only one pronouueed feeling for the house 
flj% and that is of deep disgust. Other creatures 
there are plenty of an equally offensive production, 
but the hou?e fly is pre-eminent for habitually 
insinuating its low-bred filthy self into man's 
abode, 'ly fouling our food and drink with its 
dung-stuiued feet, by soiling our all with its 
flecks of excrement, scattering germs of foul 
disease for our injury. 
We are reminded of the fact that though we 
abhor many an insect with little reason, chiefly 
on sentimental grounds, w« are in a great 
measure indifferent to the filth-bred house fly 
to comman in our dwellings, thronging eating 
rooms, swarming in baker's shops and meal 
stalls, and blackening over the baskets of sellers 
of sweet meats which our children are permitted 
to eat. 
The number of distinct (described) species of 
flies is said to be 40,000 . Of all the nnmber, only 
about half a dozen h abitually enter dwellings, 
but the most abundant by far is the one species 
Musca domestica — the universal house fly, indeed 
the "fly." 
The only part of the house fly's anatomy worth 
describing is its mouth. This organ is described 
as thick throughout, extending down from the 
head to the ground as the fly stands in feeding, 
but at other times retracted out of sight. It is 
expanded at the end and adapted for lapping and 
sucking, not for piercing. 
The house fly is first an elongate white egg, 
which hatches very quickly, sometimes in less 
than 8 hours, into a footless white maggot. This 
grows rapidly, and in about a week in warm 
weather is about g inch, in length when it is full 
grown. The maggot retracts in length, and with 
hard and darkened surface enters into the quiescent 
pupa stoge. In from 5 to 7 days the fly is 
developed and set free. 
The house fly is an all-the-year pest but is 
more numerous at certain seasons. The average 
number of eggs laid by a female is 120 per diem. 
The mission of the fly is that of a scavenger, and 
particularly so in its larval stage, but strangely 
enough tiiough the fly is so common, little of an 
exact nature is known of its breeding places. 
Horse dung is believed to be the chief food of the 
maggots, but the dung of cattle and other 
animals is also freely resorted to. The maggots, 
not being hardy, succumb as the food dries out. 
They appear to thrive in pure horse dnng, other 
forms of ordure being too compact unless broken 
up or mixed with straw. The ideal breeding place 
would appear to be manure mixed with bedding 
and saturated with urine, especially if such a 
mixture be found in a cool shady place. Badly 
kept stables are their favourite haunt, and almost 
all stables serve as breeding ploces, while places 
where scavenged rubbish is thrown (such as over- 
cultivated grass fields) are very suitable. It would 
be well here to add that kitchen waste so com* 
monly allowed to accumulate near dwellings is 
well calculated to breed the house fly. 
The relation of the house fly to disease and the 
remedies against the pest will be referred to io 
our next issue. 
{To be concluded^) 
