870 ORDER VIII. MYXOBACTERALES 



Fruiting body: Primary cysts vary in Vegetative colony: A mass of dark fruit- 

 size up to 200 microns in diameter, are irreg- ing bodies develops at the center of the 

 ular in shape and are enclosed in a colorless colony on filter paper; margin, grayish yel- 

 slime envelope. Formed by an accumulation low. The cellulose fibers are covered with 

 of secondary cysts. Secondary cysts at first vegetative cells on the outside and contain 

 colorless, transparent, later becoming many cells within. 



brownish with a limiting membrane; the Ph3\siology: Destroys cellulose. Culti- 



young cysts appear dirty yellow, the older vated six years with cellulose as a carbon 



ones grayish brown to black. Secondary source. 



cysts measure 5 to 12 by 6 to 15 microns; Source: Isolated from sandy soil in pine 



average 6 by 10 microns. On filter paper not woods in Poland. 



only well formed primary cysts are formed Habitat: Soil. Decomposes cellulose, 



but also free secondary cysts are noted em- Illustrations: Krzemieniewskis {ibid., 



bedded in the slime of the colony. PI. Ill, Figs. 17-21). 



FAMILY IV. POLYANGIACEAE JAHN, 1924. 

 (Beitrage zur bot. Protistologie. I, Die Polyangiden. Geb. Borntraeger, Leipzig, 1924.) 



Po.ly.an.gi.a'ce.ae. M.L. neut.n. Polyangium type genus of the family; -aceae ending 

 to denote a family; M.L. fem.pl.n. Polyangiaceae the Polyangium family. 



The resting cells are shortened and usually somewhat thickened rods which are always 

 enclosed in cysts. The cysts may be sessile, occurring either singly or in groups and en- 

 veloped in a slime membrane, or they may be raised on stalks (cystophores) which can be 

 either simple or branched. Cysts can occur either singly or in clusters at the tips of the 

 stalks. 



Key to the genera of family Polyangiaceae. 



I. Cysts embedded in slime; sessile, occurring singl}^ or as loose aggregates. 



Genus I. Polyangium, p. 870. 

 II. Cysts never embedded in slime; either borne on stalks or arranged in tight clusters 

 joined together at the base. 



A. Many cysts united at base to form a large disc or rosette; either sessile or stalked. 



Genus II. Synangium, p. 877. 



B. Cysts not united at base; borne singly or in large numbers on stalks. 



1. Cysts borne singly on a stalk. 



Genus III. Podangium, p. 877. 



2. Numerous cysts on a stalk. 



Genus IV. Chondromyces, p. 879. 



Genus I. Polyangium Link, 1809. 

 (Mag. d. Ges. Naturforsch. Freunde zu Berlin, 3, 1809, 42.) 



Po.ly.an'gi.um or Po.ly.an.gi'um. Gr. adj. poly many; Gr. noun angium vessel; M.L. 

 neut.n. Polyangixim many vessels. 



Cysts rounded or coiled and surrounded by a well developed membrane; either free or 

 embedded in a second slimy layer. 



The type species is Polyangium vitellinum Link. 



Key to the species of genus Polyangium. 



I. Not parasitic on algae. 



A. Sorus not white or grayish in color. 



