from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The hard, siliceous bivalve shell of a diatom.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The siliceous shell of a diatom.
from the GNU version of the Collaborative International Dictionary of English
- n. The siliceous shell of a diatom. It is composed of two valves, one overlapping the other, like a pill box and its cover.
from The Century Dictionary and Cyclopedia
- n. A small fragment.
- n. The silicious shell of a diatom; a testule.
Electrodes were inserted through the frustule into the cytoplasmic rich nuclear region of the cell (photomicrograph inset, scale bar 20 µm).
The approximately cyclindical cells (50-70 µm long by 20-40 µM in diameter) were impaled though the silica frustule aided by capacitance over compensation.