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MAYFLOWER
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MAYFLOWER , the See also:vessel which carried from See also:Southampton, See also:England, to See also:Plymouth, See also:Massachusetts, the Pilgrims who established the first permanent See also:colony in New England. It was of about 18o tons See also:burden, and in See also:company with the " Speedwell " sailed from Southampton on the 5th of See also:August 1620, the two having on See also:board 120 Pilgrims. After two trials the " Speedwell " was pronounced unseaworthy, and the " Mayflower " sailed alone from Plymouth, England, on the 6th of See also:September with the too (or 102) passengers, some 41 of whom on the 11th of See also:November (o.s.) signed the famous " Mayflower Compact " in See also:Provincetown Harbor, and a small party of whom, including See also: These insects are universally aquatic in their preparatory states. The eggs are dropped into the See also:water by the See also:female in large masses, resembling, in some species, bunches of grapes in See also:miniature. Probably several months elapse before the See also:young larvae are excluded. The sub-aquatic See also:condition lasts a consider-able See also:time: in Cloeon, a genus of small and delicate species, See also:Sir J. Lubbock (See also:Lord See also:Avebury) proved it to extend over more than six months; but in larger and more robust genera (e.g. Palingenia) there appears See also:reason to believe that the greater See also:part of three years is occupied in preparatory conditions. The larva is elongate and campodeiform. The See also:head is rather large, and is furnished at first with five See also:simple eyes of nearly equal See also:size; but as it increases in size the homologues of the facetted eyes of the imago become larger, whereas those See also:equivalent to the ocelli remain small. The antennae are See also:long and See also:thread-like, composed at first of few See also:joints, but the number of these latter apparently in-creases at each See also:moult. The mouth parts are well See also:developed, consisting of an upper See also:lip, powerful mandibles, maxillae with three-jointed palpi, and a deeply quadrifid labium or See also:lower lip with three-jointed labial palpi. Distinct and conspicuous maxillulae are associated with the See also:tongue or hypopharynx. There are three distinct and largethoracic segments, whereof the prothorax is narrower than the others; the legs are much shorter and stouter than in the winged See also:insect, with monomerous tarsi terminated by a single claw. The See also:abdomen consists of ten segments, the tenth furnished with long and slender multi-articulate tails, which appear to be only two in number at first, but an intermediate one gradually develops itself (though this latter is often lost in the winged insect). Respiration is effected by means of See also:external gills placed along both sides of the dorsum of the abdomen and hinder segments of the See also:thorax. These vary in See also:form: in some species they are entire plates, in others they are cut up into numerous divisions, in all cases traversed by numerous tracheal ramifications. According to the researches of Lubbock and of E. Joly, the very young larvae have no breathing See also:organs, and respiration is effected through the skin. Lubbock traced at least twenty moults in Cloeon ; at about the tenth rudiments of the wing-cases began to appear. These gradually become larger, and when so the creature may be said to have entered its " nymph " See also:stage; but there is no condition analogous to the pupa-stage of insects with See also:complete metamorphoses. There may be said to be three or four different modes of See also:life in these larvae: some are fossorial, and form tubes in the mud or See also:clay in which they live; others are found on or beneath stones; while others again swim and crawl freely among water See also:plants. It is probable that some are carnivorous, either attacking other larvae or subsisting on more See also:minute forms of See also:animal life; but others perhaps feed more exclusively on See also:vegetable matters of a See also:low type, such as diatoms. The most aberrant type of larva is that of the genus Prosopistoma, which was originally described as an entomostracous crustacean on See also:account of the presence of a large See also:carapace overlapping the greater part of the See also:body. The dorsal skeletal elements of the thorax and of the anterior six abdominal segments unite with the wing-cases to form a large See also:respiratory chamber, containing five pairs of tracheal gills, with lateral slits for the inflow and a posterior orifice for the outflow of water. Species of this genus occur in See also:Europe, See also:Africa and See also:Madagascar. When the aquatic insect has reached its full growth it emerges from the water or seeks its See also:surface; the thorax splits down the back and the winged form appears. But this is not yet perfect, although it has all the form of a perfect insect and is capable of See also:flight; it is what is variously termed a " pseud-imago," " sub-imago " or " See also:pro-imago." Contrary to the habits of all other insects, there yet remains a pellicle that has to be See also:shed, covering every part of the body. This final moult is effected soon after the insect's See also:appearance in the winged form; the creature seeks a temporary resting-place, the pellicle splits down the back, and the now perfect insect comes forth, often differing very greatly in See also:colours and markings from the condition in which it was only a few moments before. If the observer takes up a suitable position near water, his coat is often seen to be covered with the See also:cast sub-imaginal skins of these insects, which had chosen him as a convenient See also:object upon which to undergo their final See also:change. In some few genera of very low type it appears probable that, at any See also:rate in the female, this final change is never effected and that the creature See also:dies a sub-imago. The winged insect differs considerably in form from its sub-aquatic condition. The head is smaller, often occupied almost entirely above in the male by the very large eyes, which in some species are curiously See also:double in that See also:sex, one portion being pillared, and forming what is termed a " See also:turban," the mouth parts are aborted, for the creature is now incapable of taking nutriment either solid or fluid; the antennae are See also:mere short bristles, consisting of two rather large basal joints and a multi-articulate thread. The prothorax is much narrowed, whereas the other segments (especially the mesothorax) are greatly enlarged; the legs long and slender, the anterior pair often very much longer in the male than in the female; the tarsi four- or five-jointed; but in some genera (e.g. Oligoneuria and See also:allies) the legs are aborted, and the creatures are driven helplessly about by the See also:wind. The wings are carried erect : the anterior pair large, with numerous See also:longitudinal nervures, and usually abundant trans-See also:verse reticulation; the posterior pair very much smaller, often lanceolate, and frequently wanting absolutely. The abdomen consists of ten segments; at the end are either two or three long multi-articulate tails; in the male the ninth See also:joint bears forcipated appendages; in the female the oviducts terminate at the junction of the seventh and eighth ventral segments. The See also:independent opening of the genital ducts and the See also:absence of an ectodermal vagina and ejaculatory duct are remarkable archaic features of these insects, as has been pointed out by J. A. Palmeri. The sexual See also:act takes place in the See also:air, and is of very short duration, but is apparently repeated several times, at any rate in some cases. Ephemeridae are found all over the See also:world, even up to high See also:northern latitudes. F. J. Pictet, A. E. See also:Eaton and others have given us valuable See also:works or monographs on the family; but the subject still remains little understood, partly owing to the See also:great difficulty of preserving such delicate insects; and it appears probable they can only be satisfactorily investigated as moist preparations. The number of described species is less than 200, spread over many genera. From the earliest times See also:attention has been See also:drawn to the enormous abundance of species of the family in certain localities. Johann Anton Scopoli, See also:writing in the 18th See also:century, speaks of them as so abundant in one place in See also:Carniola that in See also:June twenty See also:cart-loads were carried away for manure! Polymitarcys See also:virgo, which, though not found in England, occurs in many parts of Europe (and is See also:common at See also:Paris), emerges from the water soon after sunset, and continues for several See also:hours in such myriads as to resemble See also:snow showers, putting out See also:lights, and causing inconvenience to See also:man, and annoyance to horses by entering their nostrils. In other parts of the world they have been recorded in multitudes that obscured passers-by on the other See also:side of the See also:street. And similar records might be multiplied almost to any extent. In See also:Britain, although they are often very abundant, we have scarcely anything analogous. See also:Fish, as is well known, devour them greedily, and enjoy a veritable feast during the short See also:period in which any particular species appears. By anglers the common See also:English species of Ephemera (vulgata and danica, but more especially the latter, which is more abundant) is known as the " may-fly," but the terms " See also:green See also:drake " and " See also:bastard drake " are applied to conditions of the same species. Useful See also:information on this point will be found in Ronalds's Fly-See also:Fisher's See also:Entomology, edited by Westwood. Ephemeridae belong to a very See also:ancient type of insects, and fossil imprints of allied forms occur even in the Devonian and Carboniferous formations. There is much to be said in favour of the view entertained by some entomologists that the structural and developmental characteristics of may-flies are sufficiently See also:peculiar to See also:warrant the formation for them of a See also:special order of insects, for which the names Agnatha, Plectoptera and Ephemeroptera have been proposed. (See See also:HEXAPODA, NEUROPTERA.) (R. McL.; G. H. 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