The dangers of house-flies to the health of the community have come into such recent prominence that the appearance of Major Hurlstone Hardy's book should fill a want. It is written lucidly and clearly, yet in that popular style which is so frequently lacking in scientific works. This is a great advantage. Too often scientists are prone to bring out works couched in terms which cannot be understood by an interested public that is not versed in technical terms. Thus matter which is of the greates

With the present day zeal for popularising interest in common things (called nature study) there has arisen the demand for knowledge practically useful and thoroughly up-to-date, yet in a form free from much of the technical terminology and treatment which are essential in the student's more fully developed scientific handbook. The "House-fly" is a fit subject for a simplified study of this kind, and the present booklet is an attempt to afford information very different to that of the "popular"

Although there are several other kinds of flies which occasionally visit the dwellings of mankind, there is one super-abundant species, Musca domestica , to which the name of "house-fly" pre-eminently belongs. In the scientist's discriminating judgment, when viewed microscopically, it differs substantially from others; but it differs very little in general appearance from certain outdoor flies and from one not uncommon indoor smaller companion, Fannia canicularis , which is not classified amongs

Just as the common "house-fly" and the "lesser house-fly" are often in error regarded as the same species with an insignificantly small difference of size, so the identity of each in turn may be confused with several other species which are not uncommon, but they are all normally outdoor flies. The chief of these is the excessively common stable-fly, Stomoxys calcitrans , whose generic and specific designations are well given, for they mean "sharp-mouth," "kicking," the latter word denoting the

The family of the Œstridæ is the most curious and horrific of all the different tribes of flies; it is very limited in species, of which five or six are prevalent throughout Great Britain. The worst of these could be almost exterminated with ease, but unfortunately mistaken ideas have prevailed, and graziers commonly believe that though the sheep's nostril fly is conspicuously harmful and dangerous, the horse's bot-fly and its congeners are negligible as regards the practical health of the host.

Whereas the blue-bottle rarely enters the dwellings of mankind, except gravid females led by the sense of smell in search of fish, or flesh meat, and (less eagerly) sweets, both species of house-fly and both sexes seem to delight in the mere odour of humanity; breeding females will seek the larder and the dust-bin, but others will very provokingly pervade all quarters. Although avoiding a dark or deeply shaded room, the house-fly seems to like partial shade; it will be content to remain indoors

The house-fly has quite the typical insect form, inasmuch as there are three well defined sections of body—the head, the chest or thorax, and the abdomen; also it has three pairs of legs, each with nine joints, of which five joints constitute what may be called the foot. The twelve segments of the maggot are observable as twelve rings in the puparium, but in the fly the three which form the thorax look like one, whilst the eight which should theoretically exist in the abdomen look like four or f

It might be supposed that a strongly developed house haunting proclivity would not be consistent with a disposition to roam far afield from the locality of birth. Many clever experiments have been made with marked flies released and recaptured within measured distances and times. After an immensity of pains taken, very little profitable knowledge has been arrived at thereby. Little of what we really want to know is indicated by such a fact as that, out of hundreds or of thousands of marked flies

Flies, which are such insidious and pertinacious persecutors of man and beast, are themselves the prey of innumerable enemies; many species are much sought for by birds, they are devoured by lizards and toads, and they are equally preyed upon by predaceous insects. Those flies which have bodies with banded colours, and which otherwise somewhat resemble bees and wasps, probably escape being the victims of some birds; but the tribe of flies does not, like the beetles, the lepidopteræ, and some oth

The house-fly may seem at first much less to be dreaded than any one of the painfully "biting" or (to be correct) skin-piercing and blood-sucking flies; yet it should be regarded as a much greater enemy to humanity and a more dangerous peril than any of those other flies, of which some short mention and description has now been given. Its life-history and its fecundity have been already alluded to; its rapid growth and maturity counterbalance the fact that it is short lived. From ancient times t

We have seen in Chapter VIII that the checks which Nature has imposed upon the prolific breeding of the house-fly have been insufficient to protect civilised mankind from ancient times continuously up to the present day. This defect need now no longer be endured; but, alas, communities and individuals are ever slow to be warned, and averse to practise newly advised methods of sanitation. In few other directions is there greater promise of advancement in general public health and comfort than by

Many minor plans have been proposed for obviating or alleviating the perils and plague of invading fly swarms; several such plans may be well carried out on a private domestic scale, but one cannot expect any of them to be adopted universally. In domestic methods people will prefer some one plan, some another, whilst some will not personally aid in the work of fly destruction in any single way perseveringly. This latter circumstance emphasises the necessity of a dominant control by local authori

It is often asked—have not house-flies some use in Nature? The only true answer is that they are warning signals. They certainly do join with a multitude of other flies in promiscuous scavenging services, and they can be very active agents therein; but this work only aggravates the fact of their dangerous partiality to mankind, together with all his belongings and surroundings. These creatures may well be imagined to have developed out of some primæval species by reason of the increase of mankin

Several authors of recent books, and lately also able lecturers, have done much to awaken people to a realisation of the dangers of our ever recurrent summer plague of flies. The advent of the petrol motor-car and other automobile vehicles has at the most but very slightly improved the state of affairs within town areas, where mews were formerly much more numerous. The public press has followed suit, but something more in the way of a sustained effort for hygienic reform is desirable. The terrib

This Index, together with the following "Table of Wing-cells and Veins," the "Glossary," and plates , II, III, IV, V, VI and VII, will explain the theoretical Diagram entitled The Fly Chart, illustrating characteristic features and exterior parts, by the study of which the reader may learn to differentiate all the sixty families which contain species native to Great Britain. A = the Head, comprising nine regions and parts (A, I to A, IX). A, I, the Vertex, which contains (1) the Ocellar Triangle

O, 1.—Costal Cell (undivided), or Costal Areolet. O, 1 a 1 .—The Humeral Cell } O, 1 a 2 .—Second Costal Cell } Costal Cell, when divided. O, 1 b .—Subcostal Cell } O, 2.—Marginal Cell (resting on V, 2). O, 3.—Submarginal Cell (resting on V, 3). O, 4 1 .—Cell resting on 4 1 (the 1st part of V, 4), a "basal" cell. O, 4 2 .—Cell resting on 4 2 (the 2nd part of V, 4). O, 4 b .—Cell resting on 4 b (a lower branch of V, 4). O, 5 1 .—Cell resting on 5 1 (the 1st part of V, 5), a "basal" cell. O, 5 2 .

II.—CECIDOMYIDÆ 1. Epidosis longipes, ♂ 2. Asphondylia sarothamni III.—MYCETOPHILIDÆ 3. Sciara thomæ 4. Mycetophila cingulum 5. Mycetobia pallipes 6. Macrocera lutea IV.—BIBIONIDÆ 7. Bibio marci, ♀ 8. Scatopse notata V.—SIMULIDÆ 9. Simulium reptans VI.—CHIRONOMIDÆ 10. Chironomus plumosus 11. Ceratopogon femoratus, ⚲ 12. Clunio marinus IX.—CULICIDÆ 13. Mochlonyx velutinus 14. Corethra plumicornis, ♀ XII.—LIMNOBIDÆ 15. Limnophila dispar 16. Rhipidia maculata, ⚲ 17. Erioptera flavescens 18. Trichoc

Nos. Refs. Families —Notes I —. Pulicidæ : fleas regarded as flies with atrophied or undeveloped wings. About 30 native species. II 3. Cecidomyidæ : mostly gall-gnats, minute and midge-like, or very frail, slender and gnat-like. Cecidomyia destructor is the notorious Hessian-fly, injurious to cereal crops. III 10. Mycetophilidæ : fungus-gnats; 34 genera; many common species. The marvellous "army-worm," the larvæ of Sciara militaris , which (being not a feeder on fungi) may be classified either s

1 (141). Insects with the head distinct from the thorax, with one pair of wings, one pair of halteres, 5-jointed tarsi, proboscis not spirally coiled; with a well defined pupal stage intermediate between the larval stage and the perfect insect. 1-1/2 (52-1/2). Frontal lunule absent. Sub-order I. ORTHORRHAPHA (comprising 25 families); flies with "mummy-pupæ," see plate VI, figs. 38 and 39. 2 (25). Antennæ many-jointed ( plate II). NEMATOCERA (thread-horns)— 3 (4). Vein endings round the margin (