260 INDEX TO AMERICAN BOTANICAL LITERATURE 
vee F. re formosa (Pfeiff.) Jac. Monats. Kakteenk. 
148. 1922. [Illust.| 
Vries, H. de Age and area and the mutation theory. In 
Willis, J. C., Age and area 222-227. 1922 
Waksman, S.A. The influence of soil reaction upon the growth 
of Actinomycetes causing potato scab. Soil Sci. 14: 61-76. 
Jl 1922. 
Walker, L. B. The forceful ejection of the glebal mass by 
Sphaerobolus. Proc. Nebraska Acad. Sci. 5: 23-25. S 1922. 
Walton, G. P. Specific acidity of water extract and oxalate 
content of African sorrel. Bot. Gaz. 74: 158-173. f.-Z.- 
16 O 1922. 
Rumex abyssinicus Jacq. 
Waterman, W. G. Development of plant communities of a 
sand ridge region in Michigan. Bot. Gaz. 74: 1-31. f. I-12. 
5.51932, 
Weaver, J. E., & Crist, J. W. Relation of hardpan to root 
penetration in the Great Plains. Ecology 3: 237-249. 
i4. Jb 1922. 
Weber, G. F. - Septoria diseases of cereals. Phytopathology 12: 
449-470. pl. 29, 30 + f. 1-5. 5 D 1922. 
Includes Leptosphaeria avenacea, sp. nov. 
Weberbauer A. Las zonas de Iluvia y de vegetacion en el 
departamento de Piura y la provincia de Jaen [Peru]. 
Arch. Asoc. Peruana Prog. Cien. 1: 107-117. 1921. 
Weingart, W. Cereus Rothii Weingart, spec. nov. Monats. 
Kakteenk. 32: 146-148. N 1922. 
From Paraguay. 
Weingart, W. Cereus Spegazzinii Web. und Verwandte. 
Mcnats. Kakteenk. 32: 161-163. D 1922. 
Welles, C. G. Cercospora leaf-spot of Averrhoa ae 
Philipp. Jour. Sci. 19: 747-752. pl. 1, 2. D 1921. 
Welles, C. G. Cercospora leaf-spot of coffee. ee Jour. 
Sci. 19: 741-746. pl. 1, D 1921. 
