380 BOOKS AND CUREENT LITERATURE 



to greater activity, but soils lacking nitrifying power failed to respond 

 to liming, results "contributory to the fact that the nitrifying flora 

 of the soil cannot be developed merely by the use of lime in the absence 

 of other factors more fundamental." Two per cent mannite appeared 

 to be toxic, for no fonnation of nitrates occurred in cultures to which 

 it had been added. 



In the opinion of the reviewer these interesting and valuable studies 

 might be repeated with profit by some of the agricultural experiment 

 stations in the dry-farming region of the West. — J. G. Brown. 



Orange Rusts of Rubus. — Announcement was made by Kunkel 

 (Bull. Torr. Bot. Club, 40: 361-366, 1913) about three years ago of 

 the fact that the aeciospores of Caeoma nitens Burrill germinate by the 

 production of a promycelium and sporidia. A recent paper^ clears up 

 the problem of the relationship of Gymnoconia interstitialis (Schlecht) 

 Lagerh., which was left unsolved in the earlier report. Two forms of 

 orange rust are found to occur within the United States and the Caeoma 

 stage of each of them is morphologically alike. The germination of the 

 one, Caeoma nitens, however, is teleutoid and of the other, aecidioid. 

 The former is thus a short cycled rust like Endophyllum, whereas the 

 other is the aecial stage of Gymnoconia interstitialis, as shown by ger- 

 mination studies, inoculations, and collections. The short cycled 

 form appears to be the one so destructive to cultivated species of 

 Rubus in this country. — Frederick A. Wolf. 



1 Kunkel, L. O. Further studies of the orange rusts of Rubus in the United 

 States. Bull. Torr. Bot. Club 43: 559-569, figs. 5, 1916. 



