LITERATURE CITED 235 



upon the germination of chlamydospores of Ustilago zeae (Beckm.) 



Ung.," /. Agr. Research, 34: 137-147, 1927. 

 Pratt, R., "Growth of germ tubes of Erysiphe spores in deuterium oxide," 



Am. J. Botany, 25:422-431, 1936. 

 "The influence of the proportions of KH 2 P0 4 ,i\IgS04, and NaNCX in 



the nutrient solution on the production of penicillin in surface cul- 

 tures," Am. J. Botany, 32: 528-535, 1945. 

 Raeder, J. M., and W. M. Bever, "Spore germination in Puccinia glumarum 



with notes on related species," Phytopathology, 27:767-789, 1931. 

 Rippel, K., "Untersuchungen iiber die Abhangigkeit der Sporenkeimung 



vom Wassergehalt der Luft bei Cladosporium fulvwn Cooke und 



anderen Pilzen," Arch. Mikrobiol., 4: 530-542, 1933. 

 Rosen, H. R., and L. M. Weetman, "Longevity of urediospores of crown 



rust of oats," Ark. Agr. Expt. Sta. Bull., 391: 3-20, 1940. 

 Smart, R. F., "Influence of external factors on spore germination in the 



Mvxomycetes," Am. J. Botany, 24: 145-159, 1937. 

 Smith, E. C, "The longevity of myxomycete spores," My col., 27:321-323, 



1929. 

 Smith, J. H., "The killing of Botrytis cinerea by heat, with a note on the 



determination of temperature coefficients," Ann. Appl. Biol., 70:335- 



347, 1923. 

 Spaulding, P., and A. Rathbun-Gravatt, "Longevity of the teliospores and 



accompanying urediospores of Cronarthtm ribicola in 1923," /. Agr. 



Research, 37:901-916, 1925. 

 Stock, F., "Untersuchungen iiber Keimung und Keimschluchwachstum der 



Uredosporen einiger Getreideroste," Phytopath. Z., 3:231-280, 1931. 

 Tsaugi, H., "Studies on the physiology of the conidiospores, conidia, and 



oospores of Sclerospora graminicola (Sacc.) Schroet. on the Japanese 



millet [Setaria italica (L.) Beauv.]," /. Imp. Agr. Expt. Sta., 2:225-252, 



1933. 

 Uppal, B. N., "Relation of oxvgen to spore germination in some species of 



Peronosporales," Phytopathology, 16: 285-292, 1926. 

 Walker, J. C, and F. L. Wellman, "Relation of temperature to spore 



germination and growth of Urocystis ceptdae" J. Agr. Research, 



32: 133-146, 1926. 

 Webb, R. W., "Studies in the physiology of fungi. XV. Germination of the 



spores of certain fungi in relation to hydrogen-ion concentration," Ann. 



Mo. Botan. Garden, 8: 282-341, 1921. ' 

 Weimer, J. L., and L. L. Harter, "Temperature relations of eleven species 



of Rhizopus," /. Agr. Research, 24: 1-39, 1923. 

 Ziegenspeck, H., "Die physicalische Chemie der zwar benetzbaren Sporen 



und sagespanformigen Samen," Biol. Generalis, 10:615-656, 1934. 



