Manson and Bancroft suggested that the second host of the parasite is the mosquito or gnat, and for a long time it was thought that they were conveyed to man by the mosquito dying after laying her eggs in water, the larval nematodes escaping from her body and being swallowed by man.
A gnat pupa swims through the water by powerful strokes of its abdomen, while the caddis-fly pupa, in preparation for its final ecdysis, bites its way out of its subaqueous protective case and rises through the water, so that the fly may emerge into the air.
In many aquatic larvae we find that all the spiracles are closed up, or become functionless, except a pair at the hinder end which are associated with some arrangement - such as the valvular flaps of the gnat larva or the telescopic " tail " of the drone-fly larva - for piercing the surface film and drawing periodical supplies of atmospheric air.
The gnat larva, for example, breathes at the tail-end, hanging head-downwards from the surface-film.
The distinctive term has no zoological significance, but in England the "mosquito" has commonly been distinguished from the "gnat" as a variety of larger size and more poisonous bite.
Before the end of the 19th century this discovery of the blood parasite of malaria was crowned by the hypothesis of Patrick Manson, proved by Ronald Ross, that malaria is propagated by a certain genus of gnat, which acts as an intermediate host of the parasite.
Mosquito, a gnat, diminutive of mosca, a fly), a term originally applied to many species of small blood FIG.
As the common gnat (Culex pipiens), are rarely found away from human habitations; others seldom or never enter houses, but are met with either in more or less open country, or in the recesses of forests and woods.
Their insect origin appears to have been entirely unsuspected until within comparatively recent times, though Pliny, indeed, makes the observation that a kind of gnat is FIG.
Schaudinn (50), who investigated certain avian Trypanosomes, considered the latter view to be correct, and believed that the carrier - in this instance a gnat - is indeed the definitive host, i.e.
The distribution of the parasites in the gnat is closely connected with the process of digestion.
To this life-cycle belongs the formation of sexual individuals and their conjugation on arrival in the gnat (Culex); the process is described as agreeing in the main, in both cases, with what has already been made known by MacCallum for another species of Halteridium.
It is the northernmost home of the opossum, grey fox, fox squirrel, cardinal bird, Carolina wren, tufted tit, gnat catcher, summer tanager and yellow-breasted chat.
It may also be used beneficially in preventing the attacks of insects, such as the onion gnat and turnip fly, by dusting the plants or dressing the ground with it.
There are also two species of owl, three species of sea-mew, the stockdove, quail, raven, magpie, chaffinch, goldfinch, blackcap, canary, titmouse, blackbird, house-swallow, &c. As to the insects, mention may be made of a species of gnat or mosquito which is sometimes troublesome, especially to strangers.
Savya a the left) becomes in Zend havaya; bhrajabi (it glitters), Zend cer razaihi; gnaT (7uv,~), Zend gena.
Thus, in comparing the insects with one another, we find that the gnat, which weighs 460 times less than the stag-beetle, has 14 times more of surface.
The gnat, for example, weighs 97,000 times less than the pigeon, and has 40 times more surface; it weighs three millions of times less than the crane of Australia, and possesses 140 times more of surface than this latter, the weight of which is about 9 kilogrammes 500 grammes (25 lb 5 oz.