from
The Collaborative International Dictionary of English v.0.48
Attraction sphere \At*trac"tion sphere\
1. (Zool.)
(a) The central mass of the aster in mitotic cell
division; centrosphere.
(b) Less often, the mass of archoplasm left by the aster
in the resting cell.
[Webster 1913 Suppl.]
2. (Bot.) A small body situated on or near the nucleus in the
cells of some of the lower plants, consisting of two
centrospheres containing centrosomes. It exercises an
important function in mitosis.
[Webster 1913 Suppl.]