106 INDEX TO AMERICAN BOTANICAL LITERATURE 
Smith, G. M. Cytological studies in the Protococcales—III. Cell 
structure and autospore formation in Tetraedron minimum (A. Br.) 
Hansg. Ann. Bot. 32: 459-464. pl. 15. O 1918. 
Soth, B. H. The arctic fleabane. Am. Bot. 24: 121, 122. N 1918- 
[Ulust.] 
Soth, B. H. Rocky mountain food plants. Am. Bot. 24: 132, 133. 
N 1918. 
Stakman, E. C., Piemeisel, F. J., & Levine, M. N. Plasticity of 
biologic forms of Puccinia graminis. Jour. Agr. Research 15: 221- 
250. pl. 17, 18. 28 O 1918. 
Standley, P. C. Rubiales. Rubiaceae (pars). N. Am. Fl. 32: 
1-86. 28 D 1918. 
w species in Portlandia (2), Tsidorea (1), Houstonia (1), Neomazoea 
(1), Acrosynanthus (4), and Rondeletia (8). 
Stevens, F. L., & Dalbey, N. E. New or a Porto Rican 
fungi. Mycologia 11: 4-9. pl. 2, 3. Jal 
Includes the new genera Septoriopsis and Wageria ine new species in Exosporium 
(t), Ramularia (1), Haplographinm (x), Microclava (1), Mycosphaerella (1), and 
Stephanomea (1). 
Stevens, H. E. Florida citrus diseases. Florida Agr. Exp. Sta. Bull. 
150: 1-110. f. 6-54. Au 1918. 
Stevenson, J. A. La enfermedad de las raices de la Cafia. Revista 
Agr. Puerto Rico 1: 269-279. f. ;0-52. O 1918. 
St. John, H. Further notes on Potamogeton. Rhodora 20: 191, 192. 
17 D 1918. 
Suksdorf, W. Cardamine eee and its near allies. Rhodora 20: 
197-199. 17 D 1918. 
Tanaka, T. New Japanese fungi. Notes and translations—V. My- 
cologia 10: 285-288. 23 N 1918. 
Thomas, H. E. Report of the plant pathologist. Rep. Porto Rico 
Agr. Exp. Sta. 1917: 28-30. S 1918. 
Waksman, S. A. The importance of mold action in the soil. Soil 
‘Sei. 6: 137-155. Au 1918. 
Weir, J. R., & Hubert, E.E. A study of heart-rot in western hemlock. 
U. S. Dept. Agr. Bull. 722: 1-37. f. 1-13. 220 1918. 
Whetzel, H. H. An outline of the history of phytopathology. 1-130. 
Philadelphia. 1918. [Ilust.] 
Wolfoff, M.I. The influence of ammonium sulfate on the germination 
and growth of barley in sand and soil cultures kept at different 
moisture contents and at various osmotic concentrations of the 
soil solution. Soil Sci. 5: 421-479. f. 1-6. Je 1918. 
