[Vol. 10 



18 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Morphology: Bacillus phytophthorus a fairly thick, colorless, rod- 

 shaped organism. Breadth averages 0.8 p, length 1.2-1.5 |j. Usually oc- 

 curring singly, occasionally in pairs. Motile by means of (usually 

 six) peritrichic flagella, stained by Peppier method. Gram negative. 



Cultural features: Liquefaction of gelatin saccate. Gelatin colonies 

 small, yellow-white, with entire margin. Agar colonies small, glisten- 

 ing, bluish-opalescent. Growth on agar stroke rapid, moderate to 

 abundant. Upon sterilized potato plugs a weak honey-yellow growth 

 develops. On sterile raw potato slices, growth and browning in 15-18 

 hours after inoculation. In 2 days middle line sinks and surrounding 

 tissue becomes dark on upper surface. A liquid is pressed out. Growth 

 in potato juice rapid and abundant. Growth in nutrient broth 

 moderate, turbid and sediment. 



Physiology : Gas from sucrose and maltose. No gas in shake cul- 

 tures of sugar agar. Nitrates reduced to nitrites. Milk coagulated 

 slowly, acid (?) curd. Pathogenic to potato stems and tubers. Index 

 No. 5?12-32120-???1. 



Smith's description of B. phytophthorus Appel. — Inasmuch as 

 Appel's ('03) original diagnosis of his species is meager, the fol- 

 lowing compilation of E. F. Smith's ('20) description is pre- 

 sented : 



A white, rapid-growing, non-sporiferous, Gram-negative, motile, 

 peritrichiate-flagellate, promptly liquefying, nitrate-reducing, aerobic 

 and facultative anaerobic, acid-forming, gas-forming, milk-curdling 

 (by formation of an acid), dry-air-sensitive, rod-shaped or filamen- 

 tous schizomycete, forming quickly on agar plates circular, grayish 

 white, well-developed colonies; on very thin-sown gelatin plates char- 

 acteristic, rapid-growing, big, circular, opaque white colonies. Organ- 

 ism white on most media but on Soyka's milk rice it is pale pinkish 

 cinnamon. Bouillon clouded very quickly and gelatin stabs develop a 

 prompt funnel of liquefaction. The organism does not form indol, 

 and does- not grow in Cohn's solution. It produces a non-volatile acid 

 from dextrose, saccharose, lactose, galactose, and maltose, and small 

 quantities of gas from inosit (muscle sugar), lactose, and mannite. 

 Pathogenic to potato shoots. Index No. 5312-32120- ?212. 



Bacillus solanisaprus Harrison. — Summary given herewith is 



compiled from Harrison's ('07) original description: 



Morphology : Bacillus of variable size. From 24-hour-old beef agar 

 spores not seen; flagella peritrichic; organism Gram negative. 



Cultural features: Growth in agar abundant, glistening, opalescent; 

 persistent growth on potatoes; uniform growth in gelatin cultures, 

 filiform liquefaction ; strong growth in nutrient broth; ring in sur- 

 face growth; clouding strong, fluid turbid, fine sediment; growth in 

 gelatin colonies slow, round to elliptical; agar colonies round to len- 

 ticular, shiny, entire. 





