SUMMARY: Light microscopy observations of a sp. of blue-green alga suggested that the sheath was comparable with the capsules of many bacteria. The sheath showed little internal differentiation under normal or phase-contrast illumination. It possessed a somewhat hazy outer margin from which portions sloughed off, it stained with Alcian blue and was probably polysaccharide. The sheath formed salt-like complexes with proteins at appropriate low pH values which rendered it visible by phase-contrast microscopy. The composition of the culture medium influenced sheath formation. Electron microscopy showed that the sheath consisted of a micro-fibrillar network containing small numbers of larger fibrils (about 200 Å in diameter) which was compressed into stria near to the cell wall and expanded into an open reticulum further out. It would appear to be formed by continuous secretion through the longitudinal walls of the trichomes, and as the outermost regions imbibed water the network structure expanded and finally sloughed off.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error