somite

Definitions

  • WordNet 3.6
    • n somite one of a series of similar body segments into which some animals are divided longitudinally
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Webster's Revised Unabridged Dictionary
    • n Somite sō"mīt (Anat. & Zoöl) One of the actual or ideal serial segments of which an animal, esp. an articulate or vertebrate, is composed; somatome; metamere.
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Century Dictionary and Cyclopedia
    • n somite An actual somatome; any one morphological segment of an articulated body, such a body being viewed as composed of a longitudinal series of somites; an arthromere or metamere of an articulate invertebrate or a diarthromere of a vertebrate; such a segment considered with or without the appendages it may possess; in the latter restricted sense, a metamere minus its appendages, or a segment of the soma or trunk without the limbs it may bear. The term sometimes extends to ideal somatomes, or to the metameres of which an organism is theoretically assumed to consist; but it is especially applied to the actual segments of such invertebrates as insects, crustaceans, and worms, whose body-rings are usually evident, though some or other of them may coalesce, as into a cephalothorax, etc. In such cases the primitive or morphological somites are usually recognized and reckoned by their respective pairs of appendages. Separate somites, continued thronghout the body, are evident in the rings of earthworms and other annelids. In arthropods the typical number of somites is supposed to be twenty or twenty-one, numbers often actually recognizable. In insects the head is assumed to have six or seven somites, the thorax has normally three (see prothorax, mesothorax, and metathorax), and the abdomen is supposed to have ten or eleven. Each of these somites is invested and indicated by a body-ring or crust of integument, primitively or typically composed of eight sclerites, which may variously coalesce with one another, or with pieces of another somite, or both. Those sclerites which ordinarily remain distinct, and thus can be identified, take special names, as tergite, pleurite, sternite, scutum, præscutum, etc., epimeron, epipleuron, etc. Appendages of somites are limbs in the broadest sense, nnder whatever modifications; and these modifications are usually greatest at the cephalic and caudal ends of the body, as into eyestalks, antennæ, palpi, mandibles, maxillæ, maxillipeds or gnathopodites, etc., of the head, and stings, claspers, or other anal armature. Intermediate somitic appendages are ordinary legs and wings, as of the thorax of insects, and the pereiopods, pleopods, chelæ, rhipidura, telson, etc., of the thorax and abdomen of crustaceans. In worms such appendages chiefly occur in the form of parapodia (neuropodia and notopodia). See sclerite, and cuts under Amphithoë, Apus, Buthus, Scorpionidæ, Blattidæ, and cockroach.
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Chambers's Twentieth Century Dictionary
    • n Somite sō′mīt a segment of the body of an articulated or vertebrate animal: an arthromere or metamere
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Etymology

Webster's Revised Unabridged Dictionary
Gr. sw^ma body

Usage

In literature:

The mesoblast appears as solid mesoblastic somites.
"Text Book of Biology, Part 1: Vertebrata" by H. G. Wells
A dorsal view of an embryo with five pairs of mesoblastic somites.
"Development of the Digestive Canal of the American Alligator" by Albert M. Reese
Metamere: a segment, somite or athromere.
"Explanation of Terms Used in Entomology" by John. B. Smith
Die politische Oekonomie ist somit wesentlich eine historische Wissenschaft.
"A Lecture on the Study of History" by Lord Acton
The tergal elements of the somites bearing the antennae, mandibles and maxillae appear to be represented by the head-shield or cephalite.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 6" by Various
The simple identification of somite with somite in Limulus and Scorpio seemed to be threatened by this discovery.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 3" by Various
The prostomium is essentially a part or outgrowth of the first somite, and cannot be regarded as itself a somite.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 6" by Various
To which somites of the thorax are the wings attached?
"A Guide for the Study of Animals" by Worrallo Whitney
Frequently, however, this exoskeletal somite may be differentiated into various regions.
"Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7" by Various
The number of limb-bearing somites in the insectan head is thus seen to be seven.
"Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 4" by Various
They have a small carapace, which only involves the first two thoracic somites, the rest of the somites being distinct.
"The Life of Crustacea" by William Thomas Calman
The mesoblastic somites are more fully developed.
"The Works of Francis Maitland Balfour, Volume 1" by Francis Maitland Balfour
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In science:

For example, the data vectors v we analyze in Section 4 are ordered within a somite-formation cycle; so vj is a measurement taken before vj+1 in the cycle, where j + 1 is understood mod n.
The Cyclohedron Test for Finding Periodic Genes in Time Course Expression Studies
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