Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/899

Rh M O S M S high latitudes they are driven off by anointing the body with fish-oil ; and in hot climates &quot; mosquito curtains &quot; are part of the ordinary bed-furniture. It is only the female that bites ; and, as it is but a very small proportion of them that can ever taste human blood or that of any warm-blooded animal, blood would not appear to be essential to their wel fare. It has been suggested that warm blood may have an influence on the ova, but it cannot be supposed that the eggs of those multitudes of individuals that never get a chance to taste blood are necessarily infertile ; everything tends to prove the opposite. Of late mosquitoes have been accused of playing a hitherto unsuspected part in the dissemination of certain entozoic diseases. According to the researches of Drs Manson and Cobbold and others, it appears certain that the insects, in sucking the blood of persons who are hosts of the entozoon known as Filaria sanguis-kominis, take these parasites into their own system, and it is believed that they afterwards (by their death and otherwise) con taminate drinking water with them, and thus convey the entozoa into the blood of persons previously unaffected. Mosquitoes are aquatic in their early stages. The FIG. 2. A, larva of Culex ; B, pupa. (After Packard.) Flo. 1. Mosquito (CwZe). A, natural size ; B, enlarged. (After Curtis.) female deposits her eggs in boat-shaped masses on the surface of the water. The larvae are very active, and have a peculiar jerking mo- tion ; the last segment is furnished with a respiratory apparatus, the form of which pro bably varies according to the species, but it is usually a long tube, the extremity of which can be exposed to the external air. The pupae are also active (contrary to the condition in most dipterous pupae), and are odd-looking creatures owing to the great development of the thoracic region ; the respiratory ap paratus is in the thorax in this state, the extremity of the body having two swimming-plates ; the pupae do not eat, but their activity is very great. No notice of the mosquito or gnat would be complete without an explanation of the mouth-parts by which it is enabled to cause such extreme irritation. When these parts are closed one upon the other the whole looks like a long proboscis ; but in reality this consists of seven distinct slender pieces separated to the base, viz. the labium, two maxillse, two mandibles, the lingua, and the labrum. The nomenclature of the mouth-parts varies with different authors. G. Dimmock (Anatomy of the Mouth-parts and of the SucL-ing-apparatu. 1 ! of some Diptcra), the latest investigator of this complex apparatus, states that the labium has for function, for the most part, the protection of the fine seta? which form the true piercing organ of Culex. In the female of Culcx the protective sheath is formed by the labium alone. When the mosquito has found a place which suits it for piercing for it often tries different places on our skin before deciding on one it plants its labcllre lirmly upon the spot, and a moment later the labium is seen to be flexing backwards in its middle ; the seta-, firmly grouped together, remain straight and enter the skin. When the seta; have entered to nearly their full length, the labium is bent double beneath the body of the insect. When the mosquito wishes to withdraw the seta; it probably first withdraws the two barbed maxilla; beyond the other setoe, that is, so that their barbs or papilla; will be kept out of action by the mandibles and hypopharynx ; then it readily withdraws the sete, perhaps aiding their withdrawal by the muscles FIG. 3. Mouth-parts, &c., of female Culex (after Dimmock). a, antenna 1. ; c, clypeus ; h, hypopharynx; lr-e, labrum - epipharynx ; I, labium; m, mandibles ; mx, maxilla: (with the tip of one of them enlarged). of the labium, for during the process of extracting the set;e from the skin, while they are slowly sinking back into the groove upon the upper side of the straightening labium, the mosquito keeps the labellse pressed firmly upon the skin. The withdrawal of blood is effected by means of a pumping apparatus at the base of the mouth - parts. As no investigator appears to have been able to detect a poison gland, it has been considered that the irri tation caused by the bite of a mosquito was solely of mechanical origin ; but the extreme irritation and its duration have not caused this idea to be commonly accepted. Dimmock avows his belief that there is use made of a poisonous saliva. In the male of Culex- the mouth -parts vary considerably from those of the female, a conspicuous point of difference being that in this sex the mandibles are absent, and the maxilla are not barbed. About 35 species of Culex (mosquito or gnat) have been described as inhabiting Europe, and about 130 from the rest of the world, but their differentiation is involved in great difficulty and uncer tainty, and it is probable that the number of true species may be very much less. A species from Cuba has received the name Culex mosquito ; but there is not one species that specially deserves the name more than another from a popular point of view, nor from a scientific point of view is there any difference between a mosquito and a gnat. MOSQUITO COAST. See NICARAGUA. MOSSES, or Musci, one of the two divisions of the botanical class Muscinex, which includes also the Liver worts or Hepaticae. See MusciNHiE. MOSSLEY, a manufacturing town of Lancashire, England, is situated on the London and North-Western Kail way and on the Huddersfield canal, near the west bank of the Tame, which here separates Lancashire from Cheshire, 3 miles north-east of Ashton-under-Lyne, and 10 east-north-east of Manchester. The houses are for the most part built of stone. To supersede the old church of St George, erected in 1757, a new building was begun in 1881. A mechanics institute was erected in 1858. In the vicinity of the town is an eminence called Hartshead Pike, on which is a lofty circular tower surmounted by a spire rebuilt of stone in 1758. Mossley has risen into importance since the introduction of the cotton manufacture about fifty years ago. A fair is held annually. The town was placed under the Local Government Act in 1864, the district to which its provisions extend including also part of Saddle- worth in Yorkshire. The total population was in 1871 10,578, and 13,372 in 1881. MOSTAR, the chief town of Herzegovina, is built on both banks of the Narenta, about 35 miles from its mouth, and 40 miles south-west of Seraievo (Bosna Serai), the capital of Bosnia. Among the public buildings are a palace, two Greek churches, and forty mosques, in several cases with Roman or Byzantine tracery in their windows. The fine old bridge from which the town takes its name