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See also:TERN (Norsk taerne, tende or tende; See also:Swedish tarna; Dutch Stern1) , the name now applied generally to a See also:group of See also:sea-birds, "Starn " was used in See also:Norfolk in the 19th See also:century as a name for the See also:bird commonly known as the See also:black See also:tern, thus confirming See also:Turner, who, in 1544, describes what seems to have been the same ae• -•:—' er_ .''r formation of workers, of neoteinic forms, or of soldiers, the last passing through the See also:stage of the See also:young worker . He attributes this deviation, which may take See also:place at various periods, to the See also:influence of See also:food, and attaches See also:special importance to the salivary food . The soldiers have no wings; nevertheless a larva, or young nymph that has the rudiments of wings, can be made into a soldier . Grassi has found juvenile specimens that have already assumed the soldier See also:form, although they possess the rudiments of wings . It appears from his observations that the worker may be considered as a form with arrested development, and the soldier as a form with arrested and much diverted development, while the neoteinic forms are individuals in which the reproductive See also:organs are perfectly See also:developed, while some of the bodily structures have suffered See also:arrest of development and even some amount of See also:atrophy . The soldier form of See also:termite presents most difficult questions to the biologist, its special structures bearing no approximation to any characters possessed by the parents . Various theories have been proposed to See also:account for this fact, but they are See also:mere guesses . We may, however, mention that it is possible that soldiers and workers occasionally produce young . This has never been actually observed, but specimens have been found with the sexual organs partially developed, and F . Silvestri has recorded the occurrence of workers with some of the characters of the See also:females, in See also:South See also:America, in a See also:nest of Termes st•unchii . the sub-See also:family Sterninae of the gulls or Laridae, but, according to P . J . See also:Selby, properly belonging,. at least in the Fame Islands, to the See also:species known by the See also:book-name of See also:Sandwich tern, all the others being those called sea-swallows—a name still most commonly given to the whole group throughout See also:Britain from their See also:long wings, forked tail and marine See also:habit . In F . See also:Willughby's Ornithologia (1676), however, the word tern is used for more than one species, and, though it does not appear in the older See also:English dictionaries; it may well have been from See also:early times as See also:general a name as it is now . Setting aside those which are but occasional visitors to the See also:British Islands, six species of terns may be regarded as indigenous, though of them one has ceased from ordinarily breeding in the See also:United See also:Kingdom, while a second has become so rare and regularly appears in so few places that mention of them must for prudence See also:sake be avoided . This last is the beautiful roseate tern, Sterna dougalli; the other is the black tern, Hydrochelidon See also:nigra, belonging to a genus in which the toes are only See also:half-webbed, of small See also:size and dark leaden-See also:grey plumage . It is without doubt the Sterna of Turner, and in former days was abundant in many parts of the fen See also:country,l to say nothing of other districts . Though nearly all its See also:ancient abodes have been drained, and for its purposes sterilized these many years past, not a See also:spring comes but it shows itself in small companies in the eastern counties of See also:England, evidently seeking a breeding-place . All around the See also:coast the diminution in the See also:numbers of the remaining species of terns is no less deplorable than demonstrable . The Sandwich tern, S. cantiaca—named from the place of its See also:discovery, though it has long since ceased to inhabit that neighbourhood—is the largest of the British species, equalling in size the smaller gulls and having a dark-coloured See also:bill tipped with yellow, and dark legs . Through persecution' it has been exterminated in all its See also:southern haunts, and is become much scarcer in those to which it still resorts . It was, however, never so abundant as its smaller congeners, the so-called See also:common and the See also:arctic tern—two species that are so nearly alike as to be beyond discrimination on the wing by an See also:ordinary observer, and even in the See also:hand require a somewhat See also:close examination ? The former of these has the more southern range, and often affects inland situations, while the latter, though by no means limited to the Arctic circle, is widely distributed over the See also:north and mostly resorts to the sea-coast .
Yet there are localities where, as on the Farne Islands, both meet and breed, without occupying stations apart
.
The See also:minute diagnosis of these two species cannot be briefly given
.
It must suffice here to See also:state that the most certain difference, as it is the most easily recognizable, is to be found in the See also:tarsus, which in the arctic tern is a See also:quarter of an See also:inch shorter than in its kinsman
.
The remaining native species is the lesser tern, S. minuta, one of the smallest of the genus and readily to be distinguished by its permanently See also: Temminck's name S. aretica, applied to the latter a See also:year afterwards, has, however, been most generally used for it.the adults in summer plumage wearing a black cap and having the upper parts of the See also:body and wings of a more or less See also:pale grey, while they are mostly lighter beneath . They generally breed in association, often in the closest proximity—their nests, containing three eggs at most, being made on the See also:shingle or among herbage . The young are hatched clothed in variegated down, and remain in the nest for some See also:time . At this See also:season the parents are almost regardless of human presence and expose themselves freely . At least half-a-dozen other species have been recorded as occurring in British See also:waters, and among them the See also:Caspian tern, S. caspia, which is one of the largest of the genus and of wide See also:distribution, though not breeding nearer to the shores of England than on See also:Sylt and its neighbouring islands, which still afford lodgings for a few pairs . Another, the See also:gull billed tern, S. anglica, has also been not infrequently shot in England . All these species are now recognized—though the contrary was once maintained—as inhabitants of North America, and many go much farther . S. forsteri is the North See also:American, and S. melanogaster the See also:Indian tern . Terns are found all over the See also:world, and among See also:exotic forms may be particularly mentioned the various species of See also:noddy (q.v.) . Often confounded with these last are the two species called in books sooty terns (S. fuliginosa and S. anaestheta), but by sailors " See also:egg-birds " or " wide-awakes " from their cry . These See also:crowd at certain seasons in innumerable multitude to certain islands within the tropics, where they breed, and the wonderful assemblage known as " wide-awake See also:fair " on the See also:island of See also:Ascension has been more or less fully described from very ancient times . W .
See also:Dampier in his voyage to New See also: |
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