Vol. 60, 1909 - University of North Carolina at Chapel Hill

98
THE CHARLOTTE MEDICAL JOURNA]
are required for the normal development, ical standpoint when preventive measures
and they hatch in about twenty-four hours are considered. -;
after oviposition. The freshly-hatched The role of this common pest in the trans- t
larvae or maggots are .07 inch in length, mission of infectious agents has come to be |j
tapering or pointed at the head end and recognized to the extent that both scientific J
blunt at the other. When fully grown they and lay papers are laying a great deal of S
are from .25 to .41) inch .in length. They stress on the importance of dealing with *i
monitor change their skins three times, methods of prevention. Dr. Henry Skinner, 1
and the entire life of the larvae is from five president of the Entomological Society of 1
to seven days. After the third molt it America, recently published in the New 3
changes to an inactive or resting stage, the Orleans Medical and Surgical Journal an J
pupa or puparium. This is a small, elou- article on this subject, from which article j
gate brown, segmented, object, rounded at we quote freely. The knowledge of bacte- ^
the ends and contains the chrysalis. This riology, in conjunction with a knowledge of <
latter stage lasts from five to seven days, the habits of the house-fly, its settling on 3
when the imago appears. Thus, the whole all kinds of food, in addition to its habit of t
life cycle is about fifteen days. alighting on all sorts of effete germ-laden jj
The bodv of Musca domestica is black; material, show conclusively that it is a very |
the head has a longitudinal reddish, oval, dangerous insect, so far as the health of |
smooth area on the vertex, with the orbits mankind is concerned. t
and adjacent region golden or silvery in The keynote to the situation is along the 9
some lights; the hairs are black and the line of prevention. Horse-manure bears 3
antenna and plume black. The thorax is about the same relation to the house-fly that ]
black, tinged with golden rays on the sides, stagnant water does to the mosquito. If 1
with three dorsal gray longitudinal bands, this insect is prevented from ovipositing in
the middle one most distinct, the two later- manure, the fly as a pest would be largely '.,
al ones partially interrupted in the middle a thing of the past. Various substances j
and continued onto the scutellum; there is have been mixed with manure to destroy
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a broad lateral golden gray band interrupt- the fly larvae, such as kerosene, chloride of t.
ed by the sutures. The base of the first lime, "residual-oil, " lime and phosphates. V
abdominal segment has a yellowish band These have been used with more or less S
interrupted in the middle- On the middle success. Stables should have smooth and 7
of the end of the two segments is a trian- hard floors and kept clean, so that manure ^
gular mesial golden spot, with an irregular cannot accumulate. It should either be i
band on each side, and farther down the used at frequent intervals or stored in prop- ; j
sides golden; terminal segment, golden, erly constructed bins or screened apart- '*:
Base of wings, scales and halteres, yellow- ments. A good method is to ram it tightly
]
ish white. Legs black. The male differs in barrels that can be tightly covered. The
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from the female in the front between the most economical way of caring for very '
eyes, being about one-third as wide as in
the latter, while she is rather the smaller.
Length, .22 to .32 inch.
large quantities has not been determined. -^
In towns and villages it would probably pay J
to have it collected at stated intervals, as is '
The tongue is comparatively short, fleshy the case with garbage and ashes. The auto- >
and bilobed and blunt, incapable of biting mobile may become a factor m ths destruc- ,,
or piercing the human skin, and is adapted tion of house-flies, as in the near future the .{
only for lapping up liquids. Allied species ^°^^^ "^^y have only a hmited use. The
which bite may be confused with the house- problem is a very simple one, and as soon ^
fly as preventive measures are inaugurated '
The legs are very hairy and the fly, in
walking on rough surfaces, uses the tarsal
claws, and, on smooth surfaces, a fleshy
organ called the pulvillus, which secretes a
fluid that enables the fly to hold on to glass
.
more extensively the effective andeconomi- ']
cal measures will be discovered.
THE INBRVB TMBORY OP A^GIN|C%
PECTORIS.
Multiple theories have been advanced to
or like surface. account for the symptom complex to which '\
This insect will oviposit in horse-manure, the term angina pectoris has been applied. ,(
decayed vegetables, decayed meats, cow- The familiar arioial theory by which many \
dung, fowls' dung and human excrement, authorities have sought to explain the .\
The vast majority of them are, however, manifestations does not cover the ground, ]
bred in horse excrement, Further knowl- for the very good reason that in many fatal
edge in regard to the food of the larva is cases autopsy reveals absolutely no anato- J
desirable. It would be useful to know about mical lesions of the coronary vessels. The
what proportion breed in garbage and in de- nerve theory advanced by von Neusser seems
cayed meats, as this is important from a med- to fulfill the requirements and to explain j
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