208 INDEX TO AMERICAN BOTANICAL LITERATURE 
Quehl, L. Die Frucht der Mamillaria echinoidea Quehl. Monats. 
Kakteenk. 23: 182. 15 D 1913. 
Quehl, L. Mamillaria arida Rose spec. nov. Monats. Kakteenk. 23: 
Sr. 15 LF 19%s. 
Rangel, E. Nota preliminar sobre molestia da Bertalha (Basella 
rubra L.) A Louvra. 17: 136-140. f. 1-8 Au 1913. 
Reed, G.M. The powdery mildews—Erysiphaceae. Trans. Am. Mic. 
Soc, 32: 219-258. pl. 13-16. O 1913. 
Reed, H. S. The enzyme activities involved in certain fruit diseases. 
Ann. Rep. Virginia Agr. Exp. Sta. 1911, 1912: 51-77. 1913. 
Reed, H. S., & Cooley, J. S. The effect of Gymnosporangium on the 
transpiration of apple trees. Ann. Rep. Virginia Agr. Exp. Sta. 
IQII, I912: 82-90. f. 16. 1913. 
Reed, H. S., & Cooley, J. S. The effect of the cedar rust upon the 
assimilation of carbon dioxide by apple leaves. Ann. Rep. Virginia 
Agr. Exp. Sta. 1912, 1912: 91-94. f. 17. 1913. 
Reed, H. S., & Crabill, C. H. Plant diseases in Virginia in the years 
1911 and 1912. Ann. Rep. Virginia Agr. Exp. Sta. 1911, 1912: 
35-50. f. 2-14. 1913. 
Reed, H. S., & Holmes, F. S. A study of the winter resistance of the 
uredospores of Puccinia coronata Cda. Ann. Rep. Virginia Agr. 
Exp. Sta. 1911, $912: 78-81. f. 15. 1913. 
Ridgway, C.S. The occurrence of callose in root hairs. Plant World 
16: 116-122. f. 1-12. Ap 1913. 
Rigg, G. B. Forest distribution in the San Juan Islands: a preliminary 
note. Plant World 16: 177-182. f. 1-4. Je 1913. 
Saccardo, P. A. Notae mycologicae. Series XVII. Ann. Myc. !- 
546-568. 31 D 1913. 
Includes I. Fungi Mexicani, II. Fungi Canadenses, and III. Fungi Dakotenses. 
Twenty new American species are described. 
Schaffner, J. H. Laboratory outlines for general botany. [Ed. 3] 
1-125. pl. t, 2+ f. 1-17. Columbus. 1913. 
Schreiner, O., & Skinner, J. J. Experimental study of the effect of 
some nitrogenous soil constituents on growth. Nucleic acid and its 
decomposition products. Plant World 16: 45-60. F 1913. [Illust-] 
Seaver, F. J. The genus Pseudoplectania. Mycologia 5: 299-3°?- 
pl. 109, I10. 25 N 1913. 
Sharp, L. T. Some bacteriological studies of old soils. Plant World 
16: 101-115. Ap 1913. 
