NOV. 22, I915 
Occurrence of Manganese in Wheat 
355 
(5) I do not wish to draw conclusions from my facts relative to the 
essential character of manganese as a mineral constituent of plants, 
though these facts seem to support this view for wheat and possibly for 
emmer, rye, oats, etc. It seems improbable that a nonessential con¬ 
stituent would occur in all samples and in essentially the same quantity 
under such a variety of conditions. 
LITERATURE CITED 
(1) Bertrand, Gabriel. 
1912. Sur le role des infiniment petits chimiques en agriculture. In Ann. Inst. 
Pasteur, t. 26, no. 11, p. 852-867, 1 fig. 
(2) BrEnchlEy, Winifred E. 
1910. The influence of copper sulphate and manganese sulphate upon the growth 
of barley. In Ann. Bot., v. 24, no. 95, p. 571-583, 4 fig., pi. 47. See 
also [Rothamsted Exp. Sta., Harpenden, Eng.] Rothamsted Mem. Agr, 
Sci., v. 8, 1902-1912. 1914. 
(3) Guthrie, F. B., and Cohen, L. 
1910. Note on the occurrence of manganese in soil, and its effect on grass. In 
Agr. Gaz. New South Wales, v. 21, pt. 3, p. 219-222. 
(4) Jost, Ludwig. 
1907. Lectures on Plant Physiology... Translated by R. J. Harvey Gibson. 564 
p., illus. Oxford. 
(5) KEEEEY, w. p. 
[1908?] The influence of manganese on the growth of pineapples. Hawaii Agr. 
Exp. Sta. Press Bui. 23, 14 p. 
(6) - f 
1914. The function of manganese in plants. In Bot. Gaz., v. 57, no. 3, p. 213- 
227. Literature cited, p. 226-227. 
(7) VOELCKER, J. A. 
1903. Pot-culture experiments, 1902. In Jour. Roy. Agr. Soc. England, v. 64, 
P- 348-3 6 4, fig- S _I 3- 
