FAMILY MYXOCOCCACEAE 



1047 



Abt., 1913, 866; Jahn, Beitriige zur 

 botanischen Protistologie. I. Die Polyan- 

 giden, Geb. Borntraeger, Leipzig, 1924, 

 86.) 



Etymology: Latin cerehrinn, brain; 

 formis, shape. 



Swarm stage (pseudoplasmodium) : 

 Rods 4 to 12 microns. 



Fruiting bodies: About 1 mm long, 

 clumped masses with swollen upper 

 surface, brain-like, violet rose, often lead- 

 gray. Cysts 100 to 170 microns, without 

 slime envelope. Spores 1.1 to 1.6 mi- 

 crons. Jahn (loc. cit.) suggests that this 

 may be Archangium gephyra. 



Source and habitat : Kofier {loc. cit.). on 

 hare dung in the vicinity of Vienna. 



Illustrations: Kofier {loc. cit.) PI. 2, 

 Figs. 7 and 8. 



7. Chondrococcus columnaris (Davis) 

 Ordaland Rucker. {Bacillus columnaris 

 Davis, Bull. U. S. Bur. Fisheries, 38, 

 1923, 261; Ordal and Rucker, Proc. Soc. 

 Exper. Biol, and Med., 56, 1944, 18; also 

 see Fish and Rucker, Trans. Amer. Fish. 

 Soc, 73, 1944 in press; Cyfophaga colum- 

 naris Garnjobst, Jour. Bact., 49, 1945, 

 113.) 



Etymology: From Latin columnaris, 

 rising in the form of a pillar. 



Vegetative cells: Flexible, weakly 



refractive, Gram-negative rods, 0.5 to 

 0.7 by 4 to 8 microns. Creeping motion 

 observed on solid media, and flexing 

 movements in liquids. 



Spores (microcj'sts) : 0.7 to 1.2 microns, 

 spherical to ellipsoidal, occurring on 

 both liquid and solid media. 



Physiology: Growth best on 0.5 to 

 0.9 per cent agar with 0.25 to 0.50 per 

 cent Bactotryptone at pH 7.3. Colonies 

 on tryptone agar yellow, flat and irregu- 

 lar. Edge uneven with swarming appar- 

 ent. Gelatin liquefied rapidly. No in- 

 dole. No reduction of nitrates. Starch, 

 cellulose and agar not attacked. Sugars 

 not fermented, but glucose oxidized. 



Fruiting bodies on agar not deliques- 

 cent, and surrounded by a firm mem- 

 brane. A peculiar type of fruiting body 

 formed in liquid media. Where organ- 

 isms are in contact with infected tissues 

 or with scales, produce columnar, some- 

 times branched, fruiting bodies in which 

 typical spores (microcysts) develop in 

 7 to 10 days. 



Source and habitat: First described 

 as cause of bacterial disease of warm 

 water fishes (Davis, loc. cit.) and later 

 in fingerlings of the cold water blue 

 black salmon {Oncorrhynchus nerka). 

 Transmissible to salmonid fishes. 



Genus III. Angiococcus Jahn. 



(Beitriige zur Protistologie. I. Die Polyangiden, Geb. Borntraeger, Leipzig, 1924, 89.) 

 A segregate from Myxococcus Thaxter. 



Diagnosis: Fruiting body consisting of numerous round (disk-shaped) cysts, cyst 

 wall thin, spores within. 



Etymology: Greek angion, vessel and kokkos, coccus (ball). 

 The type species is Angiococcus disciformis (Thaxter) Jahn. 



Key to the species of genius Angiococcus. 



A. Cysts yellow to dark orange-yellow; disk-shaped; 35 microns in diameter. 



1. Angiococcus disciformis. 



B. Cysts colorless to yellow; round; up to 15 microns in diameter. 



2. Angiococcus cellulosum. 



1. Angiococcus disciformis (Thaxter) 

 Jahn. {Myxococcus disciformis Thaxter, 

 Bot., Gaz., 37, 1904, 412; Jahn, Beitrage 



zur botanischen Protistologie. I. Die 

 Polyangiden, Geb. Borntraeger, Leipzig, 

 1924, 89.) 



