[54] Gossard, H. A. and King, J. L., Bull. 329, Ohio Agr. Exp. Sta. Sept., 1918, p. 70.
[55] Bull. Univ. Kans. Vol. 18, No. 1, Oct., 1917, pp. 301-302, Wellhouse, Walter H.
[56] Agr. Gaz. Can. Vol. 5, No. 5, May, 1918, pp. 449-454.
Transcriber's Notes:
The cover image is in the public domain.
The illustrations have been moved so that they do not break up paragraphs
Typographical errors have been silently corrected but other variations in spelling and punctuation remain unaltered.