The relationships of the bacteria and viruses to other living things.

Abstract

In the forthcoming edition of Bergey's Manual, the classification used has been rearranged on the assumption that the polar-flagellate, photoautotrophic bacteria existent today are the living organisms that are most nearly like primordial types of bacteria. The primordial bacteria—like living things out of which other living things (animal and plant) have developed—must have been preceded by other living things of a size comparable to living viruses. However, unlike filterable viruses, which represent a comparatively recent evolutionary development, primordial living things must have existed on simple, presumably inorganic foods and must have been very different physiologically from viruses. The new classification has been greatly developed by the group of specialists that have helped in the preparation of the new Manual. The (a) blue-green algae, (b) bacteria, (c) rickettsias and viruses are arranged in the improved classification as three classes in Division I, Protophyta Sachs of the Plant Kingdom. The number of orders in Class II, Schizomycetes has been increased from 5 to 10 by a subdivision of previously recognized orders and by the recognition of a recently proposed new Order X, Mycoplasmatales Freundt for the pleuropneumonia-like organisms. The classification of the rickettsias and viruses will be discussed in a separate paper.