33. Franke, W. W. and R. M. Brown, Jr. 1971.
Scale formation in chrysophycean algae. III. Negatively stained
scales of the coccolithophorid Hymenomonas. Archiv.
f. Mikrobiol. 77:12-19.
33. Summary
The two types of scales of the coccolithophorid
Hymenomonas (= Cricosphaera) carterae have been studied
with the negative staining technique. Both types of scales, including
the non-mineralized circular ones and the larger, mineralized
elliptical ones are made up of a highly ordered network of radial
and concentric fibrils. Both fibrils are ribbon shaped and have
dimensions of 10-22 X 30-75 A in cross-sections. The margin of
the scales is composed of two closely associated fibrillar ribbons
which are observed occasionally in edge view. In the elliptical
scales, the periphery of the fibrillar network often is obscured
by a deposition of the coccolith calcium carbonate. The substructure
of the fibrils, the occurrence of kinking sites, and the fibrillar
resistance to alkaline and weak acid treatments strongly resemble
the scales of Pleurochrysis scherffelii. In relation to
the recent findings of Brown and co-workers (Brown et al., 1969,
1970) on scale formation processes, it is hypothesized that the
fibrillar network of the scales of both species is structurally
and chemically identical, and that the fibrillar material consists
of a cellulose-like polysaccharide.