68 MINNESOTA BOTANICAL STUDIES. 



days in an atmosphere containing 1/20000 of NOH^ failed to ger- 

 minate. The growth of young seedlings of Zea viais kept in 

 a moist chamber for 48 hours containing i 20000 partNOH^ was 

 retarded. Growing shoots are badly affected when kept in an 

 atmosphere containing i 15000 part of NOH^. Resting bulbs 

 are not effected by being kept in an atmosphere containing one 

 part of NOH^ in 5000 of air. Salvinia nutans and Philotria are 

 killed by introducing .1 cc. of NOH^ to every 2000 cc. of 

 water. 



Chloroform and Ether. — These two reagents have a ver}' 

 similar effect upon growth. Seedlings of Zea mats kept in a 

 moist chamber containing i/ioooo part of chloroform or ether 

 show a marked acceleration in growth after release. In an at- 

 mosphere containing 1/5000 growth is greatly retarded. Rest- 

 ing bulbs and growing shoots are equally susceptible and are 

 killed after being exposed for ten to twenty days in an atmos- 

 phere containing 11 0000 part of the reagent. 



Carbon bisulphide. — The smallest trace of carbon bisulphide 

 present is injurious to growing plants, although, as G. Hicks 

 (III.) has shown, it is inoperative on resting seeds. 



Alcohol has no effect upon the growth of seedlings when 

 used in quantities not exceeding i/ioooo. If the larger quanti- 

 ties are used the growth is retarded and the seedlings are killed. 

 Resting bulbs kept in an atmosphere containing i/iooo to 1/500 

 parts of alcohol g^ew, but the floral organs were dwarfed and 

 the buds remained unopened. 



Literature to which reference is made. 



I. Detmer. Ueber die Einwirkung verschiedener Gase insbe- 

 sondere des Stickstoffoxydulgases auf Pflanzen. Landw. Jhluhr'^^ 

 213. 1882. 



II. Detmer. Das Verhalten der Pflanzen im Contact mit Stick- 

 stoffoxydulgase. Physiol. Prakt. 2 Ed., p. 235. 1895. 



III. Hicks. Bull— Bot. Div. Dept. of Agric— 1896. 



IV. Johannsen — Bot. Cent. — 1896. 



V. Moeller. Ueber Pflanzenathmung. I Das Verhalten der 

 Pflanzen zu Stickstoffoxydul. Ber. d. deut. bot. Ges. 2: 35. 18S4. 

 VI. Townsend C. O. Correlation of growth under the influence 

 of injuries. Annals of Botany. 11: 509. 1897. 



