Bacteroids

BACTEROIDS, first described by Blochman (1887), are symbiotic bacteria living in the plasma of certain cells of the fat body in cockroaches. They appear as slightly curved rods up to 8-9 μ in length. Mercier cultivated them on various media and named them Bacillus cuenoti. These symbionts also infect the eggs in the cockroach's ovary and are passed on to the next generation of insects. Phenomena of such symbiosis, in which yeast fungi (zoochlorellae, zooxanthellae, etc.) are also involved, are very widespread in the animal kingdom. Symbionts are known in many other insects, mites, worms, tunicates, and other animals in various organs and tissues. Plant symbionts sometimes play an important role for the organism, becoming like its organelles; they can digest plant cellulose and thereby make this food suitable for the organism; in other cases they

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Bacillus cuenoti give the ability to glow (firefly, pyrosoma), etc. The connection between symbionts and the host can be very close; in a number of cases, symbionts cannot be distinguished from the morphological formations of the cell, known under the name of chondriosomes or mitochondria. Mewes (Mowes) even considers them identical. The view of the cell as a collection of symbionts is extended by some researchers even further.