The ova of Culex, on the other hand, are deposited in any stagnant water, including cesspools, drains, cisterns, or water collected in any vessel; they float in boat-shaped masses on the surface.
The Oder and some of the tributaries of the Elbe abound in crayfish, and in the stagnant lakes of East Prussia leeches are bred.
Agricultural or field drainage consists in the freeing of the soil from stagnant and superfluous water by means of surface or underground channels.
These strata are practically stagnant, deficient in oxygen and surcharged with carbonic acid.
It is a stagnant, poorly built town of one-storeyed houses and mudwalled cabins, with few public edifices and business houses of a better type.
They form a region of salt lakes and stagnant marshes, relieved by wide flat spaces of open plateau country.
Broad, behind which are developed the socalled murd-db, or "dead waters," stagnant pools and swamps characteristic of this coast, and a main cause of its unhealthiness.
The temperature of the Boiling Spring the same day was 45º, or the warmest of any water tried, though it is the coldest that I know of in summer, when, beside, shallow and stagnant surface water is not mingled with it.
It was a time when, under able leaders, a great national party was beginning the struggle for reform against the stagnant Austrian government.
The efficiency of drainage, digging, hoeing and like operations is accounted for by the manner in which they promote aeration of the soil, raise its temperature and remove its stagnant water.
The streets as originally laid out were wide and spacious, but being unpaved and undrained they were no better than mud tracks diversified by piles of garbage and foul-smelling stagnant pools.
In the malarious islet of Asinara a pond of stagnant water was treated with petroleum and all windows were protected with gauze.
The latter, besides its more obvious advantages, speedily freed large tracts of country from stagnant water and their inhabitants from ague, and prepared the way for the underground draining which soon after began to be practised.
There is an obvious difficulty in assuming that Xlyvat, in the sense of " marshes," existed in this confined area, but stagnant pools may still be seen here in winter.
The existence of sulphuretted hydrogen in great quantities below loo fathoms, the extensive chemical precipitation of calcium carbonate, the stagnant nature of its deep waters, and the absence of deep-sea life are conditions which make it impossible to discuss it along with the physical and biological conditions of the Mediterranean proper.
The preliminary stages of all mosquitoes are passed in water, either fresh or salt, stagnant or slightly moving.
Jacobsen on some occasions found water in the surface layers of the Baltic supersaturated with oxygen, which he ascribed to the action of the chlorophyll in vegetable plankton; in other cases when examining the nearly stagnant water from deep basins he found a deficiency of oxygen due no doubt to the withdrawal of oxygen from solution, by the respiration of the animals and by the oxidation of the deposits on the bottom.
The family Phryganeidae have males with foursegmented hairy palps; the larvae inhabit stagnant water and make cases of vegetable fragments.
In addition, various kinds of canals and endiked or embanked lakes had come into existence, forming altogether a vast network of more or less stagnant waters.
It might indeed have been thought that thorough drainage would be unnecessary, but it must be noted that porous subsoils or efficient drains do not act merely by carrying away stagnant water which would otherwise cool the earth, incrust the surface, and retard plant growth.
Less favourable signs are furnished by such plants as Arundo Donax (in Germany), Cicuta virosa and Typha latifolia, which are found in stagnant and torpid waters.
The water should be run off thoroughly, for a little stagnant water lying in places upon the surface does much injury.
The keeping of swine in a dwelling-house, or so as to be a nuisance, is made an offence punishable by a penalty in an urban district, as also is the suffering of any waste or stagnant water to remain in any cellar, or within any dwelling-house after notice, and the allowing of the contents of any closet, privy or cesspool to overflow or soak therefrom.
The rain water stands for months in stagnant pools made by the feet of elephants.
For instance, the swampy character of malarial areas is explained by their breeding in stagnant water; the effect of drainage, and the general immunity of high-lying, dry localities, by the lack of breeding facilities; the danger of the night air, by their nocturnal habits; the comparative immunity of the upper storeys of houses, by the fact that they fly low; the confinement of malaria to well-marked areas and the diminution of danger with distance, by their habit of clinging to the breeding-grounds and not flying far.
(1) In the first place, common sense suggests the avoidance, in malarious countries, of unhealthy situations, and particularly the neighbourhood of stagnant water.
The flood plain during its formation is marked by meandering, or anastomosing streams, ox-bow lakes and bayous, marshes or stagnant pools, and is occasionally completely covered with water.
Even the Pedias (ancient Pediaeus) does not reach the sea in summer, and its stagnant waters form unhealthy marshes.
The miasmatic exhalations caused by the sun playing on stagnant waters after the floods give rise to the "Sennar fever," which drives even the natives from the plains to the southern uplands.