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
- 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
cytoplasmsurrounding the centrioleof a centrosome.
- noun geology
from Wiktionary, Creative Commons Attribution/Share-Alike License
The protoplasm surrounding the centrosphere is frequently arranged in radiating fibrillar rows of granules, forming what is termed the attraction sphere.
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.
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.