Egg-shaped mass of zoogloea of Beggiatoa roseo-persicina (Bacterium rubescens of Lankester); the gelatinous swollen walls of the large crowded cocci are fused into a common gelatinous envelope.
Zoogloea of Bacterium merismopedioides, Zopf, containing cocci arranged in tablets.
One of the most remarkable phenomena in the life-history of the Schizomy cetes is the formation of this zoogloea stage, which corresponds to the " palmella " condition of the lower Algae.
In some cases the zoogloea thread or tube has not been seen, the organism consisting entirely of the bacterioids.
Mixed zoogloea found as a pellicle on the surface of vegetable infusions, &c.; it consists of various forms, and contains cocci (a) and rodlets, in series (b and c), &c. (x 540).
C. Reticulate zoogloea of the same (x 250).
Branched fruticose zoogloea of Cladothrix (slightly magnified).
C. Zoogloea stage of a Micrococcus, forming a close membrane on infusion - Pasteur's Mycoderma.
The zoogloea is now known to be a sort of resting condition of the Schizomycetes, the various elements being glued together, as it were, by their enormously swollen and diffluent cell-walls becoming contiguous.
The zoogloea is formed by active division of single or of several mother-cells, and the progeny appear to go on secreting the cell-wall substance, which then absorbs many times its volume of water, and remains as a consistent matrix, in which the cells come to rest.
Characteristic forms may be assumed by the young zoogloea of different species, - spherical, ovoid, reticular, filamentous, fruiticose, lamellar, &c., - but these vary considerably as the mass increases or comes in contact with others.
Under favourable conditions the elements in the zoogloea again become active, and move out of the matrix, distribute themselves in the surrounding medium, to grow and multiply as before.
If the zoogloea is formed on a solid substratum it may become firm and horny; immersion in water softens it as described above.
Zoogloea pellicle (X 500).
These enter the root-hairs of leguminous plants, and passing down the hair in the form of a long, slimy (zoogloea) thread, penetrate the tissues of the root.
Cell from the epidermis of root of Pea with " infection thread " (zoogloea) pushing its way through the cellwalls.
It is these bacteria which form the zoogloea of the " mother of vinegar," though this film may contain other organisms as well.