1. Fruiting body red. a. The shortened rods 2.5 to 3 microns. 1. Archangium gephyra. aa. The shortened rods 4 to 6 microns. 2. Archangium primigenium. 2. Fruiting body yellow. 3. Archangium flavum. B. Tube usually uniformly thick, loosely wound, often branched. 4. Archangium serpens. II. Fruiting body consisting of a reddish, coiled tube embedded in yellow slime. 5. Archangium thaxteri. 1. Archangium gephyra Jahn, 1924. {Chondromyces serpens Quehl, Cent. f. Bakt., II Abt., 16, 1906, 16; Jahn, Beitrage zur bot. Protistologie. I, Die Polyangiden. Geb. Borntraeger, Leipzig, 1924, 67.) ge'phy.ra. Gr. noun gephyra a bridge (in- termediate). Swarm stage (pseudoplasmodium) : Grows easily in manure decoction, forming a pseu- doplasmodium and ring of fruiting bodies. The vegetative rods are about 10 microns long, 0.5 micron in diameter. Fruiting bodies: Up to 1 mm in diameter, of irregular form and with swollen or padded surface. Average-sized fruiting bodies are a reddish flesh color by reflected light; smaller fruiting bodies, a light rose. On a dark background, large fruiting bodies, when fresh, appear bluish violet. By trans- mitted light the fruiting bodies appear yel- lowish to light red. The inner structures are for the most part a mesenteric mass of tubes 40 to 60 microns wide, without any membrane and without any enclosing slime. The convolu- tions are often pressed together. On the inside of these tubes there appears definitely a septation by straight or slightly arched cross walls which, however, do not always cut entirely through the spore masses from one side of the tube to the other. Upon pres- sure, the fruiting body breaks up into a number of small fragments about 15 to 30 microns in diameter. Within these fragments the shortened rods lie parallel and in bun- dles. The rods in the fruiting bodies are so shortened that they resemble the spores of the Myxococcaceae. The spores are 2.5 to 2.8 microns long and about 1.4 microns wide. Often they are somewhat bent so that they appear to be bean-shaped. In the smooth, transparent tips of fruiting bodies they stand closely parallel to each other, so that in transmitted light one sees only their cross section and is at first led to be- lieve that he is dealing with one of the Myxo- coccaceae. Source: Found in rabbit dung. Found frequently in the region of Berlin on the dung of deer, rabbits and hare, once also on old decaying lichens. Easily overlooked on account of its usual bluish color. Habitat: Found on decaying organic matter in soil and in the dung of various animals. According to Krzemieniewski (Acta Soc. Bot. Poloniae, 5, 1927), the most common of my.xobacters in the soils of Poland. Illustrations: Quehl {op. cit., 16, 1906, PI. 1, Fig. 7), Jahn (op. cit., 1924, PI. 1, Fig. 5) and Krzemieniewski (Acta Soc. Bot. Poloniae, 4, 1926, PI. Ill, Figs. 25-26). 2. Archangium primigenium (Quehl, 1906) Jahn, 1924. {Polyangium primigenium Quehl, Cent. f. Bakt., II Abt., 16, 1906, 16; Jahn, Beitrage zur bot. Protistologie. I, Die Polyangiden. Geb. Borntraeger, Leipzig, 1924.) pri.mi.ge'ni.um. L. adj. primigenius primitive. Swarm stage (pseudoplasmodium) : In manure decoction, cysts germinate readily. Vegetative rods 4 to 8 microns in length. Fruiting bodies: Up to 1 mm in diameter, sometimes larger, with irregularly padded swollen surface; when fresh, a lively red color is produced which is quite prominent, especially against a dark background; when dried, dark red. In transmitted light flesh- red to yellowish red.
