When I formulated the concept Symprotit and its sub-unit Protit as the primeval unit of life in the form of a quite homogeneous minuscule kernel as recognized phenomenological forms of bacteria up to the outer limits of visibility, it had been well proven by their reproductive ability that these were living organisms. But all connection was lacking between these subvisible units and the higher forms of the bacteria, to say nothing of a connection to cells, which wasn’t even under consideration. For this, long years of study of their living conditions were required – and the necessary culturing experiments which were repeated in endless series over and over again. I chose as my experimental object of study the Microsphaera vaccinae (Cohn 1872), bred from various vaccine lymphs (of which it’s quite irrelevant whether or not it is the cause of smallpox, as even the discoverer of this species assumed).
What we are dealing with here is a preliminary sketch of a few excerpts from the results of these developmental-historical and comparative-morphological studies; the detailed main publication with numerous illustrations will appear in the indicated venue.
The Microsphaera vaccinae (Cohn 1872) in its typical phenomenological form is a micrococcus usually about 0.5-0.6 micron long, which nevertheless represents a Thecit and not a primary Basit (even though it is a Basit, albeit a pliovalentes one). If one puts the material of a culture of this strain in a hanging drop, then it will very quickly develop (usually beginning after just a few seconds) a mass of Chondriten, usually growing rapidly, especially when the starter material is from an older culture. By culturing material from one of these hanging drops, one can easily create isolated colonies of the Chondritstadiums, but they are only visible after a few days (and with a magnifying glass) as extremely tiny colonies among the large Thecites colonies. However, they can be isolated even sooner by simply swabbing the areas between the large colonies.
Over the years, I have steadily cultured the Thecit in numberless series out of the pure cultures of the Chondritstadiums, so that the total material of Microsphaera vaccinae (Cohn 1872) at my disposal has to a certain extent been complexly filtered. The creation of the Thecites usually takes place over weeks to months, so that a dispersion of individual Theciten, which would grow to large colonies in a single day, is out of the question.
Isolated Chondrite quickly grow in hanging drops into entire systems alternating between Symprotit and Filum, as shown here. The Symprotite here can already take on quite varied sizes. Since the Filum is capable of renewed granule formation (Symprotit) at many different locations, one after the other, it is reasonable to conclude that the Filum is a linear arrangement and organization of the final unit, the Protites.The alternation between the two growth forms of the Chondritstadiums is thus an alternation between a growth form with linear arrangement of the Protite (Filum) and one with three-dimensional arrangement of the same (Symprotite). The diameter of the Filums – about 0.02 micron or even less – is accordingly the diameter of the free Protites. But whereas the Filum – except with dark-field illumination – is usually only visible as it blinks when the mirror is moved, presumably the Protit alone is no longer clearly recognizable; only accumulation gives rise to a pocked surface, which, much like the Filum, is accounted for by the light-diffracting processes. With longer observation periods, one can now and again notice an increase in thickness – which, however, since it is usually irregularly bounded, could be due to the expulsion of individual Protiten. Even in these masses, more robust granules (Symprotite) can be formed here and there.
But the Symprotit, which is based on a three-dimensional union and organization of Protiten, can also excrete these free accumulated Protite. This generally occurs after a few days, and these loose plasma masses cling to the Symprotit in the form of an extremely fine to extended calotte: the plasma coat.
The first phase of the socialization of two development stages to a new unit is complete. The Symprotit becomes the parietal nucleus (Mych), the Protit accumulation becomes the fluid plasma, the plasma coat, and the new unit is the cell-like Mychit. The auxanogene (i.e. multiplicative) development, takes places in the alternation of Mychit and Dimychit; here, with these fission processes, the Filum has lost its mobility during its lengthening growth and has shortened to a filament in the confined space of the fluid plasma, the plasma coat. If yolk masses (reserve materials such as lipids, nucleic acid derivatives, etc.) are stored up in the Mychit, then it is chiefly on the surface of the Mych (nucleus) in the form of Trophosom (or Trophosomelle) and of the filament in the form of Trophode. I have already treated this in more detail for other bacteria (Sitzungsber. Ges. naturf. Fr. [Session reports of the society of friends of natural-science research] Berlin 1931, pp. 87-88 and Arch Entw. Bakt. [Archive for the developmental history of bacteria] I, 1, 1931 pp. 53-104). There is no need here to go into more detail on the further course of Probaenogenie to Phytit, Rhabdit, etc., since it is not relevant to present goals, and since these processes are common to all higher bacteria.
It remains only to mention that here, too, in the Microsphaera vaccinae (Cohn 1872), the formation of the spherical or slightly ovoid Cystite (with a Mych or Symmychon), Thecite (with several Mych or Symmycha) and Chondrothecite (with very numerous minuscule Mych, belonging to the Protit or Symprotit) is consummated mostly on Synasciten, but also on Mycasciten, as is usually the case, but in this species, these structures can also be formed freely, which is not otherwise normally true.