X Journal of Agricultural Research voi. xix 



Page 



37 . A. — Results of inoculations with Pseudomonas citri upon roots of sweet orange 



{Citrus sinensis). B. — Skeletonized leaves of Ellen grapefruit recovered 

 from buried soil 206 



Production of Conidia in GibberElla saubinetii 

 Text Figure 



I. Conidial production in Gibberella saubinetii (Mont.) Sacc: A, Ascospores 

 from cornstalk, germinated in distilled water, producing conidia in three 

 days; B, D, typical conidia and conidiophore from a 28-hour-old hanging 

 drop culture from a conidium from A; C, germinating conidia from a 

 52-hour-old plate culture; E, conidiophore and germinating conidia from 

 a 47-hour-old colony in a Van Tiegham cell 236 



Effect op Manure-Sulphur Composts upon the Availability of the 

 Potassium of GreEnsand 



Text Figure 



I. Diagrams showing relation of the water-soluble acidity to the water-soluble 



potassium at different time periods for different greensand composts .... 250 



Rust in Seed Wheat and Its Relation to Seedling Infection 



Text Figure 



I. Diagram of air- washing apparatus for isolated room used for growing rust- 

 infected seed 268 



Plates 



38. Heads of Kubanka durum wheat heavily infected with stemrust 277 



39. A. — Portion of one of the heads shown in Plate 38. B. — Wheat kernels 



showing typical stemrust infection 278 



40. Exterior view of isolated room in the pathological greenhouse at the Uni- 



versity of Wisconsin, showing (a) the exterior portion of air- washing 

 apparatus used to wash all air drawn into the room, (6) the canvas curtain 

 used for shading on warm days, and (c) the sprinkling attachment used to 

 throw spray of water over the roof to aid in keeping the room cool 278 



41. A. — Photograph of wheat grown in fiats in isolated room in greenhouse at the 



University of Wisconsin. B. — Same plants as A, when well headed. . . . 278 



42. Longitudinal section through hilar portion of an immatiu"e wheat kernel, 



showing sorus of stemrust 278 



43. Longitudinal section through the hilum of a wheat kernel infected with 



stemrust, showing imusually large internal sori extending nearly across 



the kernel 278 



44. Cross section of a mature wheat kernel infected with stemrust, showing 



telia in the ventral groove 278 



45. Enlarged portion of section shown in Plate 44, showing telia on surface of 



ventral groove 278 



46. Longitudinal section of embryo of germinated wheat kernel showing large 



internal rust at x in hilar tissue at base of embr>'onic tissue 278 



47. Longitudinal section of the embryo fiuther advanced in development than 



that shown in Plate 50 278 



48. Longitudinal section through young secondary root of wheat embryo, 



showing presence of intracellular mycelium 278 



