from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The mass of cytoplasm surrounding the centriole in a centrosome.
  • noun The central part of the earth, usually the part beneath the lithosphere but sometimes the part beneath the mantle.

from The Century Dictionary.

  • noun In cytology, a spherical, differentiated mass of cytoplasm surrounding the centrosome and constituting a pole of the karyokinetic spindle during cell-division. Also called attraction-sphere.
  • noun The central or interior portion of the earth, beginning at a somewhat indefinite depth, and involving materials and pressures of which we have no actual experience; contrasted with the successive outer shells, lithosphere, hydrosphere, and atmosphere.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Geol.) The nucleus or central part of the earth, forming most of its mass; -- disting. from lithosphere, hydrosphere, etc.
  • noun (Biol.) The central mass of an aster from which the rays extend and within which the centrosome lies when present; the attraction sphere. The name has been used both as excluding and including the centrosome, and also to designate a modified mass of protoplasm about a centrosome whether aster rays are developed or not.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun biology The cytoplasm surrounding the centriole of a centrosome.
  • noun geology barysphere


from Wiktionary, Creative Commons Attribution/Share-Alike License

centro- + -sphere


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  • The protoplasm surrounding the centrosphere is frequently arranged in radiating fibrillar rows of granules, forming what is termed the attraction sphere.

    I. Embryology. 1. The Animal Cell 1918

  • In the middle of the centrosome is a minute body called the centriole, and surrounding this is a clear spherical mass known as the centrosphere.

    I. Embryology. 1. The Animal Cell 1918

  • 2 Coincidently with or preceding these changes the centriole, which usually lies by the side of the nucleus, undergoes subdivision, and the two resulting centrioles, each surrounded by a centrosphere, are seen to be connected by a spindle of delicate achromatic fibers the achromatic spindle.

    I. Embryology. 1. The Animal Cell 1918


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