272 Journal of Agricultural Research voi. vi. No. 7 



(2) The apparent effect of humidity and temperature on the amount of 

 cyanid in sorghum is probably due to the indirect effect on the rate of 

 growth. 



(3) Adequate water supply is usually accompanied by low, and inade- 

 quate by high, hydrocyanic-acid content. This is probably due to the 

 need of glucosid stimulation when the water supply becomes low. 



(4) The character of the growth of the plant affects the distribution 

 of dhurrin between leaves and stalks, there being a proportionately 

 smaller amount in the thick, heavy stalks than in the slender ones. 



(5) There is no consistent daily variation in the amount of dhurrin, 

 which argues against the functioning of this glucosid as a food storage, 



(6) Of the two varieties used in this experiment, the Southern Cane in 

 every plot but one had a higher content of hydrocyanic acid than the 

 Early Amber. Varietal difference is probably of more weight in deter- 

 mining the amount of hydrocyanic acid in sorghum than are the condi- 

 tions of growth. 



LITERATURE CITED 



(i) Alway, F. J., and Trumbull, R. S. 



1910. On the occurrence of prussic acid in sorghum and maize. In Nebr. 



Agr. Exp. Sta. 23d Ann. Rpt., 1909, p. 35-36. 



(2) Armstrong, H. E., and Armstrong, E. F. 



191 1. The function of hormones in regulating metabolism. In Ann. Bot., 



V. 25, no. 98, p. 507-519. 



(3) Avery, Samuel. 



1902. Laboratory notes on poison in sorghum. In Jour. Comp. Med. and Vet. 

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(4) Balfour, Andrew. 



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(5) Briggs, L. J., and Shantz, H. L. 



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(6) Ravenna, Ciro, and Zamorani, Mario. 



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(7) Treub, Melchior. 



1907. Notice sur "I'effet protecteur" assigne a I'acide cyanhydrique des 

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(8) 



1909. Nouvelles recherches sur le r61e de 1 'acide cyanhydrique dans les plantes 

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(9) ViEHOEVER, Amo, and Johns, C. O. 



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1915. Notes on the hydrocyanic-acid content of sorghum. In Jour. Agr, 

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