14 A SPOT DISEASE OF CAULIFLOWER. 



showed no growth during this period, but clouded moderately three 

 days after removal to temperature of 18° to 20° C, and plates from 

 this tube gave pure cultures of the cauliflower organism. Plates 

 poured before and after 10 days' freezing showed considerable reduc- 

 tion in the numbers of organisms, but the growth of the livmg ones 

 was not retarded. Some tubes of beef bouillon, inoculated with a 

 3-millimeter loop h-om a 48-hour bouillon culture and kept frozen for 

 seven days, cloudea within 48 hours after removal to a temperature 

 of 18° to 20° C. Another frozen for 22 days did not cloud after 

 removal to temperatures of 18° to 20° C. The check clouded. The 

 organism grows readily at low temperatures, e. g., beef-bouillon 

 cultures clouded in seven days when kept at temperatures of 0° to 1° C. 



VITALITY ON CULTURE MEDIA. 



This organism remams alive for six to eight months at tempera- 

 tures varjdng from 18° to 24° C. on beef agar, LoeflSer's blood serum, 

 and potato cylinders, and in peptonized beef bouillon ( + 15), beef 

 gelatin (+10), milk, Uschinsky's, Fermi's, and Cohn's solutions. 

 Evaporation was not prevented in these cultures and the media 

 became concentrated, often dry, and yet the organism was frequently 

 alive. Beef- agar and beef-gelatin cultures at temperatures of 12° to 

 15° C. and subject to less evaporation (in refrigerator) were dead after 

 eight months. In media less favorable for the growth of this organism, 

 as beef bouillon plus salt, alkali, or acid, the bacteria live but two to 

 three months. 



GROUP NUMBER. 



The group number, according to the descriptive chart of the Society 

 of American Bacteriologists, is 211.3332023. 



NAME OF ORGANISM. 



This organism appears to be an undescribed form, and because of 

 the characteristic spotting of the affected leaves the name Bacterium 

 maculicolum (n. sp.) is suggested. 



LATIN DIAGNOSIS. 

 BACTERIUM MACULICOLUM (N. SP.). 



Baculis in hospite brevibus, cylindricis, apicibus rotundatis, soli- 

 tariis, saepe binis (in agar-agar quandoque 10-30 baculis in filamenta 

 conjunctis); baculis 1.5-3.0 // x 0.8-0.9 p.; 1-5 flagellis polaribus mo- 

 bilibus; aerobiis, asporis. 



Habitat in foliis vivis Brassicae oleraceae in macuhs 1-3 mm. latis, 

 purpureo-griseo colore. Coloniae gelatinam liquefacientes. Colo- 

 niac in agar-agar rotund ae, albae, nitentes. Si bacuh in petri-vasibus 

 rare seruntur, in septimo die colonae 6-8 mm. diam. sunt. Baculi 



225 



