(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 5. Growing spicules in sclerocytes obtained from primmorphs cultured in the
presence of 60 µmol l-1 silicic acid; sequence of TEM images.
(A) Two sclerocytes (scl) in the primmorph start to synthesize spicules (sp).
The blunt end of one newly growing spicule (B) is associated with
collagen-related fibrils (col), but not the second spicule (shown enlarged in
C). The sharp end of the spicule shows inhomogeneous structure (D), suggesting
less dense packing of silica in the spicule. Collagen fibers (col) surround
the two spicules.