862 EXPERIMENT STATION RECORD. 



Notes on Stewart's sweet-corn germ (Pseudomonas stewarti), 

 E. F. Smith (Proc. Amer. Assoc. Adv. Sri., 47 (1898), pp. 422-426).— The 

 author reports having received from F. 0. Stewart, of the Xew York 

 State Station, in 1898 pure cultures of the organism, which had been 

 described as the cause of a disease of sweet corn (E. S. K.,9, p. 1056). He 

 states that with some exceptions, as far as he has studied it the organ- 

 ism possesses the characters assigned to it by Stewart, and some others 

 which will help to readily distinguish it. The behavior of the organ- 

 ism on various media is fully described. It seems to be an undescribed 

 form, is motile by a single polar flagellum, and has been designated 

 Pseudomonas steicarti, n. sp. The following synopsis of characters is 

 given : 



"A medium-sized rod rounded at the ends and motile by means of one polar fla- 

 gellum, size 0.5 to 0.9 by 1 to 2jti, no spores observed ; found in enormous numbers in 

 the vascular bundles of corn (Zea mays) associated with a destructive disease of 

 which it is probably the cause; color in the host plant and in culture media yellow 

 (buff to chrome or ocher, occasionally a pale, dirty yellow) ; aerobic and facultative 

 anaerobic; grown in all ordinary culture media; bears alkali well (soda) ; and plant 

 acids extremely well; grows luxuriantly in Uschinsky's solution; growth enor- 

 mously stimulated by cane sugar, grape sugar, and galactose; growth not favored by 

 5 per cent doses of lactose, maltose, dextrin, mannite, or glycerin in nutrient starch ' 

 jelly ; diastatic action feeble, i. e., able to obtain food from starch only with much diffi- 

 culty; produces alkalies in all sorts of media and acids in the presence of grape and 

 cane sugar; reduces litmus slowly; does not liquefy gelatin; does not liquefy Loef- 

 fler's blood serum; grows well at summer temperatures of 25 to 30° C.J does not 

 die out quickly in culture media ; does not produce gas ; sensitive to light; occurs in 

 New York and Michigan, and may be looked for in all parts of the United States." 



The time for treatment of black rot in southeastern France, 

 J. Perratjd ( Compt. Bend. Acad. Sci. Paris, 126 (1898), No. 19, pp. 1377- 

 1379). — In a previous paper (E. S. E., 9, p. 761) the author has shown in 

 general the time of the different invasions of black-rot fungus in the 

 vineyards of southeastern France. In the present paper he reviews 

 experiments conducted in 1896 and 1897 for the prevention of this dis- 

 ease. In 1896, the times of the appearance of the black-rot fungus 

 were May 26, June 10 and 22, July 5 and 18, and August 1 and 17 ; and 

 sprayings were given the vines on the following dates : May 5 and 15, 

 June 1, 13, and 25, and July 8, 18, and 30. In summarizing the results 

 of the work in 1896, it is stated that 1 applications of fungicides, made 

 May 15, June 1 and 25, and July 18, were sufficient to entirely protect 

 the crop. 



In 1897 the black rot appeared in the vineyards May 28, June 23, 

 July 6 and 20, and August 4. The sprayings in this year were made 

 on May 1, 12, and 20, June 2 and 26, July 3 and 17, and August 3. In 

 this year, although the vineyard was injured by a heavy hailstorm, 98 

 per cent of the grapes were saved by treatments given the vines on May 

 12, June 2 and 26, and July 13 ; and the author states that the pres- 

 ervation would have been complete had there been a supplementary 

 treatment July 3. 



Generalizing from the experiments of the years 1896 and 1897, the 



