238 Bulletin 80 



53 Stockberger, W. W., Effect of some toxic solutions on mitosis, Bot. 

 Gaz., vol. 49, p. 416, June, 1910. 



54 Sullivan, E. C, Precipitation of natural silicates, Econ. Geol., vol. 1, 

 no. 1, p. 67, 1907. 



■>■> Vedrodi, V., Der Kupfer als Bestandtheil der Sandboden und unserer 

 Kulturpflanzen, Cliem. Zeitung, vol. 17, p. 1932, December, 1893. 



56 Viala, On the action of certain toxic substances upon the vine 

 (Tr.), Eevue de Viticulture, nos. 3 and 5, 1894. 



57 Spaeth, E. A., The vital equilibrium. Science, n. s., vol. 43, no. 1110, 

 p. 502, April, 1916. 



