864 



ORDER VIII. MYXOBACTERALES 



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. 



