1. Dorsum of thorax with four sharply defined

brown, more or less oval or elongate spots, arranged in a parallelogram, two in front and two behind the transverse suture; proboscis bulb with a sharply defined brown or dark brown tip _longipennis_, Corti. Dorsum of thorax without such spots; proboscis bulb not brown or dark brown at tip 2. Wings with upper thickened portion of anterior transverse vein much darker in colour than adjacent veins and thus standing out con- spicuously against the rest of the wing _brevipalpis_, Newstead. Wings with upper, thickened portion of anterior transverse vein not much darker in colour than adjacent veins, and thus not standing out conspicuously against the rest of the wings (wings practically unicolorous) _medicorum_, Austen.[424] [424] Newstead has recently described another species as _G. severini_ (_Ann. Trop. Med. and Par._, 1913, vii, No. 2, pp. 331–334). It is allied to _G. fuscipleuris_, Austen. *Glossina palpalis*, Rob. Desv. [This is the chief carrier of sleeping sickness in Nature. It is found in places over the whole of West Africa from the mouth of the Senegal River to Angola, and extends eastwards into the Bahr-el-Ghazal. The eastern boundary follows the valley of the Nile and includes the eastern shores of Lakes Victoria and Tanganyika; from the southern end of the lake the boundary tends south-west, approximately following the frontier between North-eastern Rhodesia and the Congo Free State, and passing through the Katanga district of the latter country into Angola (Austen). It may occur up to 3,000 ft.; but, according to Bagshawe, it has not been recorded above 4,000 ft. It feeds on the blood of many animals, including reptiles, amphibia, birds, and even amphibious fishes, as well as all the wild mammals. It seems, however, to possess a decided predilection for man, and undoubtedly thrives better upon mammals and birds than upon cold-blooded animals. [It is not usually found far from water, requiring a humid atmosphere and temperature of about 85° F. (shade). But a marked seasonal distribution is shown, the flies considerably extending their range during the rainy season, and thus visiting districts which are dry for the greater part of the year; as the rains diminish the fly gradually leaves the temporary haunts and returns to the more permanent ones. It bites only by day, and then only in sunny weather, and usually lives in shade. [Illustration: FIG. 419.--_Glossina palpalis_ and puparium. (After Brumpt.)] [Roubaud has shown that the first larva produced is about three weeks after copulation, and that others are produced at an interval of nine or ten days. The puparium stage is rapidly produced after the expulsion of the larva, often in three-quarters of an hour. The puparium stage lasts from thirty-two to thirty-five days. The puparia occur in well-drained humus close to water, sheltered by trees or bushes, in crevices in rocks, and between the exposed roots of trees, sometimes in sand. [Bruce has shown that only a very small percentage of flies fed experimentally on infected animals ultimately become infective, and that the infectivity of this small percentage depends upon a delayed infection of the salivary glands. [A variety, _wellmani_ of Austen, is found in Angola, Gambia, the Katanga district of the Congo Free State, the Matondwi Islands of Tanganyika, etc. *Glossina morsitans*, Westwood. [This species has been shown by Kinghorn and Yorke, and also by Bruce, to be responsible for the transmission of _Trypanosoma rhodesiense_, the micro-organism producing sleeping sickness in man in Rhodesia and Nyasaland and also in parts of German and Portuguese East Africa. Fisher and Taute have demonstrated experimentally that _Trypanosoma gambiense_--the sleeping sickness parasite of other parts of Africa--may also be transmitted by this fly, and in addition it is known to be capable of disseminating several species of trypanosomes pathogenic to animals. Of these, _T. brucei_ (=? _T. rhodesiense_), the parasite of tsetse disease, first incriminated by Bruce, is perhaps the most important. [Illustration: FIG. 420.--The tsetse-fly (_Glossina morsitans_, Westwood).] [It is the most widely spread of all tsetse-flies; its range extends from Senegambia in the north-west to Southern Kordofan and Southern Abyssinia in the north-east, and then southwards to the Bechuanaland Protectorate, North-eastern Transvaal and Zululand. The actual localities given by Austen are Gambia, French Guinea, Gold Coast, Togoland, Dahomey, Northern Nigeria, Congo Free State, the Bahr-el-Ghazal, the Uganda Protectorate, German East Africa, and Portuguese East Africa. [This species is confined to “belts,” often of very limited extent, and appears to prefer regions where there is sufficient vegetation for moderate but not excessive cover and a hot, moderately dry climate. It is not nearly so dependent upon water as is _G. palpalis_, and generally is most active in a dry atmosphere; some observers, however, state that in certain districts it is more common along the banks and edges of rivers. This tsetse-fly has been taken as high as 5,500 ft. altitude. It infests native villages as well as the bush. Like other tsetse-flies it bites not only during the hottest part of the day, but also on bright warm moonlight nights, and it feeds on the blood of all mammals. [The structure of the male genitalia of those representatives of _G. morsitans_ occurring on the West Coast of Africa and in parts of the Soudan presents certain constant differences from that of the typical form of this species; this form is known as _G. morsitans_, race _submorsitans_, Newst. Genus. *Stomoxys*, Geoffroy. [The members of this genus which occur in temperate and tropical countries are provided with a hard, slender, shiny black proboscis which projects horizontally from beneath the head; by means of this structure they can bite severely. In general appearance they resemble house flies, but the proboscis at once distinguishes them. In many parts of Britain they are known as storm flies on account of their frequent appearance indoors previous to a storm of rain or wind, which I have invariably found to be correct; they are also called stinging flies. In colour they are greyish, dusky or brownish-grey or black, varying from 5 to 7 mm. in length; the thorax has dark longitudinal stripes and the abdomen dark spots or bands. In the male the eyes are closer together than in the female. These flies usually occur in stables and farmyards, along woods and in lanes, and mainly attack mammals. [Illustration: FIG. 421.--The stinging fly (_Stomoxys calcitrans_, Linn.).] [One species (_Stomoxys calcitrans_, Linnæus) occurs practically all over the world. The female lays her eggs in moist, warm, decaying vegetation; as many as eighty may be laid by a single female. The ova are white, banana-shaped, with a broad groove on the shorter curvature; they may hatch in two or three days. The creamy-white larva tapers to a point at the head end, and is truncated at the tail end. Two black mouth hooks are plainly visible at the cephalic extremity. There are two plates on the posterior surface of the last segment which bear the respiratory pores, nearly circular in outline. It reaches maturity in fourteen to twenty-one days; when mature it is 11 mm. long. The pupal stage is passed in the old larva skin and lasts from nine to thirteen days; it is barrel-shaped, 5 to 8 mm. long, and of a bright reddish-brown to dark chestnut-brown colour. [This insect may act as a carrier of anthrax, and has been proved to be the agent of an extensive epidemic of malignant pustule in the Isle of Pines, New Caledonia.[425] [425] _Bull. des Séances de la Soc. ent. de France_, 1878, pp. cxliv, cxlv. [Noè’s[426] experiments tend to show that it is an intermediate host and transmitter of _Filaria labiato-papillosa_ of the ox. [426] _Atti della Reale Accad. dei Lincei, Anno CCC. Se Quinta_, 1903, xii, 2 sem. fasc., pp. 387–393. [Surra is generally stated to be transmitted by Stomoxys as well as Tabanus, and yet Nitzman in the Philippines obtained uniformly negative results in exhaustive experiments. Others have also been unsuccessful. Certainly Stomoxys can transmit the disease in French West Africa (Bonet and Roubaud), and mechanically has been proved to be capable of disseminating other trypanosomes (experimentally): sleeping sickness (_T. gambiense_); nagana (_T. brucei_); souma (_T. cazalboui_); and el debat (_T. soudanense_). [_S. calcitrans_ may also be a carrier of poliomyelitis (Rosenau and Brues, _Harvard Alumni Bulletin_, 1912, xv, No. 9, pp. 140–142). Several species are now known (_S. brunnipes_, Grünb.; _S. inornata_, Grünb.; _S. nigra_, Macq.; _S. omega_, Newst.; _S. ochrosoma_, Speiser, etc.). Genus. *Lyperosia*, Rondani. [A genus of small flies which bite man and animals, but are not so far connected with the transmission of any disease in man, but in Java it appears to carry surra (P. Schat, _Meeledeel Praefstation Oost-Java_, 1903, 3e ser., No. 44), the species being _Lyperosia exigua_, Meijere. These flies can be told from Stomoxys by the palpi being broader, flattened laterally, and as long, or nearly so, as the proboscis. When not feeding the palpi enclose the proboscis, as in Glossina. They are usually about half the size of Stomoxys, and are the smallest blood-sucking _Muscidæ_. They frequently swarm around and upon domesticated animals. [The life-history of the horn fly in America (_L. irritans_, Linn.) is well known. It lays its ova singly in freshly dropped cow-dung, and there the maggots feed, pupating in the soil beneath. [Patton and Cragg also give some details as to the life-history of _Liperosia exigua_ (“Medical Entomology,” p. 375) as follows: “_L. exigua_, whose habits have been observed in Madras, usually lays twelve eggs at a time. The flies immediately return to the cow and the process is repeated when the dung is again dropped. The larvæ migrate from the dung when about to pupate, and the puparia are always found in the earth at some distance away or under the sides of the patch of dung. The fly usually hatches out in five days, though sometimes as late as the eighth. Weiss has studied the life-history of _irritans_ var. _weisii_ from Algeria; its larval stage lasts five days, and the flies hatch out of the puparia in another five days.” [The other biting genera of _Muscidæ_, Hæmatobia, Hæmatobosca, Bdellolarynx, Stygeromyia, and Philæmatomyia, although sometimes annoying to man, have not in any way been connected with any disease. [The horse fly (_Hæmatobia irritans_, L.[427]) attacks cattle chiefly, but now and then man is bitten. The different species can be told from Stomoxys by the palpi being nearly as long as the proboscis. [427] This is apparently the _stimulans_ of Meigen. [The genus *Philæmatomyia*, Austen, is intermediate between Stomoxys and Musca in structure, and between the non-blood-sucking Musca, as _M. domestica_, and the blood-sucking _Musca pattoni_, Austen, which feeds on the blood exuding from the bites of true blood-suckers. They occur in Central Africa and India, Ceylon and Cyprus (_vide_ “The Life-history of _Philæmatomyia insignis_, Austen,” _Ann. Trop. Med. and Par._, 1912, v, p. 515). [Two flies belonging to the family *Anthomyidæ* also attack man, namely:-- [_Hydrotæa meteorica_, L. (the meteoric fly). This fly attacks man as well as animals. They especially bite around the eyes and nostrils of animals, but are not so particular with man; the head, however, is usually chosen. Linnæus called it the meteoric fly because it often forms clouds around horses’ heads at the approach of rain. The Hydrotæas are usually black or blue-black in colour with bare eyes and simple abdomen, the front femora peculiarly constructed. _H. meteorica_, L., occurs in Britain. [The members of the genus Hydrophoria, Desvoidy, also bite man. *Pupipara* or *Eproboscidæ*. [The _Pupipara_ are all blood-suckers, the majority occurring as parasites on mammals and birds, where they are more or less permanent parasites. Occasionally some may attack man. They all produce their young fully formed, and they assume the pupal stage immediately after extrusion. The puparia are large. They are mostly flat, louse-like flies which may or may not be winged. In the case of Melophagus I have found the puparia are often passed by the female. The winged forms have a short quick flight, and when disturbed will seek shelter in man’s hair or beard. Two main families occur: (1) the _Hippoboscidæ_, and (2) the _Nycteribiidæ_. The former occur on animals and birds, the latter on bats only, but may invade man. Two other families are known--the _Braulidæ_ (bee parasites) and the _Streblidæ_ (bat parasites). [The mouth of the _Hippoboscidæ_ is long and sharp, forming a proboscis. The thorax and abdomen are flat and leathery. The legs are stout and strong, and terminate in large dentate claws and other structures of use in holding on to the hair or feathers of their host when blood-sucking. [Austen says it is probable that the _Hippoboscidæ_ are descended from ancestors belonging to the _Muscidæ_, which underwent modification in bodily structure as the consequence of the adoption of a parasitic mode of life. [Two wings are present in the true Hippoboscæ, _Hippobosca equina_ (of the horse), _H. camelina_ (of the camel), _H. maculata_ (of oxen), and _H. capensis_ (of dogs), but are absent in Melophagus, the sheep tick or ked fly (_M. ovinus_). [In two genera, Lipoptena and Echestypus, wings are at first present, but are lost as soon as the fly finds its permanent host. [With regard to their biting man, such is only occasional. I have known sheep shearers to be badly bitten by _Melophagus ovinus_, and have more than once been attacked myself when standing where shearing is taking place. Sharp records the grouse parasite, _Ornithomyia lagopodis_, as once biting severely a gamekeeper in Scotland. There are also records of _H. maculata_ biting man in Africa and India. [Although so far not connected with any human disease, it is interesting to note Theiler has shown that _Hippobosca rufipes_, v. Olfers, and _H. maculata_, Leach, are capable of transmitting _Trypanosoma theileri_, Laveran, the cause of gall sickness amongst cattle in the Transvaal. It is now considered, however, that _Trypanosoma theileri_ is non-pathogenic, and that the cause of gall sickness is a piroplasma-like organism known as _Anaplasma marginale_. Theiler, Laveran and Mesnil all hold this view (_vide_ Laveran and Mesnil, “Trypanosomes and Trypanosomiases,” second edition, 1912, p. 330). [_Lynchia._--Three members of this genus have been shown to transmit the non-pathogenic (?) organism, _Hæmoproteus columbæ_ amongst pigeons in Algeria and S. America. Insects and Epidemic Poliomyelitis. [In a recent number of the _Journal of Economic Entomology_,[428] Brues and Sheppard point out the possibility of acute epidemic poliomyelitis (infantile paralysis) being an insect-borne disease. They summarize as follows:-- [428] Charles T. Brues and Philip A. E. Sheppard, “The Possible Etiological Relation of certain Biting Insects to the Spread of Infantile Paralysis,” _Journ. Econ. Ent._, 1912, cciv, pp. 305–324. [Many facts connected with the distribution of cases and the spread of epidemics of this disease with histories of insects bites, suggest at least that the disease may be insect-borne. Field work during the past summer, together with a consideration of the epidemiology of the disease so far known, points strongly towards biting flies as possible carriers of the virus. It seems probable that the common stable fly (_Stomoxys calcitrans_, L.) may be responsible to a certain extent for the spread of acute epidemic poliomyelitis, possibly aided by other biting flies such as _Tabanus lineola_. No facts which disprove such a hypothesis have as yet been adduced, and experiments based upon it are now in progress. [If the disease should prove to be common to any species of domestic animals, as is now strongly suspected, a secondary connection of ticks in spreading the disease among such animals seems probable, as has been mentioned. [The following is some of the more important literature on _Diptera_ in general: Meigen, J. W., “Syst. Besch. d. bek. europ. zweiflügligen insecten,” 1818–1838, 7 vols.; Brauer, F., “Monographie der Oestriden,” Wien, 1863; _Idem_, “Nachtr. hiersu,” _Wien. ent. Zeit._, 1887, vi, pp. 4, 71; Schiner, J. R., “Fauna austriaca: die Fliegen,” Wien, 1860–64; Löw, Fr., “Ueber Myiasis und ihre Erzeuger,” _Wien. med. Wochenschr._, 1882, xxii, p. 247; 1883, xxxiii, p. 972; Joseph, G., “Ueb. Fliegen als Schädlinge und Parasiten des Menschen,” _Deutsch. med. Zeit._, 1885, i, p. 37; 1887, iii, pp. 713 and 725; Peiper, E., “Fliegenlarven als gelegentl. Paras. d. Mensch.,” Berlin, 1900; Theobald, F. V., “Monograph of the Culicidæ of the World,” 1901–1911, 5 vols. and 1 atlas, plates; Austen, E., “A Monograph of Glossina Tsetse-flies,” 1903, 1 vol.; Van der Wulp, “Diptera neerlandica,” 1877; Walker, “Insecta Britannica: Diptera,” 1851–53 and 1856; Lundbeck, “Diptera danica,” 1907–12; Zetterstedt, “Diptera scandinaviæ,” 1850; Theobald, “British Flies,” 1892; Aldrich, “N. American Diptera,” 1905; Loew and Osten Sacken, “Monographs of the N. American Diptera,” 1862–63 and 1869; Macquart, “Diptera exotique,” 1830–47; Rondani, “Diptera exotica et Italica,” 1863–68; Williston, “Manual of Families and Genera of N. American Diptera,” second edition; Verrall, “British Flies.” A fuller literature will be found in Peiper, as well as in Huber’s “Bibliographie d. klin. Ent.,” 1899, iii, Jena, in the Bibliography at the end of this work and in the _Rev. of App. Ent._ (Dulau and Co., London), where all references to modern research can be found.--F. V. T.] ADDENDA. *Akamushi or Kedani Sickness* (_vide_ also p. 487).--Schuffner (Far East. Assoc. Trop. Med., _Compt. rend. Trois. Cong. Biennial_, 1913, Saigon, 1914, pp. 309–315) states he observed a peculiar fever in Deli, Sumatra, somewhat resembling typhoid. This he traced either to a mite or tick. He figures the possible carriers, namely, a Trombidium and _Cheyletidæ_. He calls this disease pseudo-typhus--a variant of Japanese kedani sickness, which, he says, also occurs in the Philippines. *Ticks.*--AFRICAN TICK FEVER: Marzinovsky (_Proc. of Conference of Bacteriologists and Representatives of Medical Sanitary Authorities on the Campaign against Infectious Diseases in connection with the War, Soc. Russ. Physicians in mem. Pirosov_, Moscow, 1915, pp. 56–68), states that African tick fever has been imported into Persia, and that it is there carried by _Ornithodorus tholosani_. TICK PARALYSIS: Todd (“Paralysis and Tick-bite,” _Can. Med. Assoc. Journ._, 1914, iv, No. 9, pp. 825–826) refers to paralysis ascribed to the bites of ticks in children, and possibly adults, in America, British Columbia and Australia. He states that a young child, perfectly well one day, has more or less complete paresis or paralysis on the next, fever, a rapid pulse, and other constitutional symptoms. The child may be dull and stupid, and may have convulsions. If the tick is not found and removed the child may die, but if it is removed, the symptoms disappear and recovery is complete in a few hours. The tick must be entirely removed. *Diptera.*--PSYCHODIDÆ: Bolt (_China Med. Journ._, Shanghai, xxix, No. 2, pp. 78–86) states that sand-flies (Plebotomus) and the fever due to them are common in North China, May and June being the worst months. The natives of the region appear to be immune, but all others suffer. Old ruined buildings are the favourite haunts of the Phlebotomus. The species of Phlebotomus has not been determined. *Pulicidæ.*--DERMATOPHILUS (SARCOPSYLLA) PENETRANS, OR THE “JIGGER.”--This flea (_vide_ p. 544) is believed by Lama (_Giorn. Ital. Mal. Ven._, Milan, 1914, xlix, pp. 465–472) frequently to carry leprosy and he points out that the early lesions of leprosy usually appear on the uncovered parts of the body. This flea also attacks rats. *Brachycera.*--LEPTIDÆ (_vide_ p. 603): White, A. (“The _Diptera-Brachycera_ of Tasmania,” part I, _Papers and Proc. Roy. Soc. of Tasmania_ for 1914, 1915, pp. 35–74), describes a new blood-sucking Leptid, _Spaniopsis tabaniformis_, which resembles a small gad fly (Tabanus) in appearance. _Pycnosoma putorium_: This is believed by Roubaud (“Les Producteurs de Myiases et Agents similaires chez l’homme et les animaux,” Paris, 1914,