8 T äJ-ffi m 0i m o m % 



V. Measurements of the Spores. 



In the measurements of the aecidiosporcs and uredospores, the writer has 

 used spores obtained from well matured pustules on the fresh leaves or stems. 

 They were mounted 0.5 0/0 KOI I and measured with a Zeiss eyepiece micro- 

 meter. 



A) Accidiospore. Aktiiuk who first described the life-history of the fun- 

 gus, reported the size of the aecidiosporcs to be 21 to 28 // by 19 to 2J [i in 

 diameter. So far as can be ascertained by the writer, the description of this 

 spore-form has been reported only by Aktmur. Three hundred measurements 

 were made for the aeciilios[iores from aecidia produced on the stems of the 

 seedlings in the out of doors. The result of the measurements is as follows : — 



Table T. Measureiiunts of the aecidiosporcs. 

 a. Length in lilicron. 



Table II. JMeasurentents of the aecidiospores. 

 b. Width in Micron. 



The result shows that the majorit}' of the aecidiospores are 18.0 to 28.8 }i 

 \\\ length and 16.2 to 27.0 a in width, and quite agrees with those of Arthur. 



B) Uredospore. The writer got the specimens of the fungus on the variety, 

 "Saginaw" from his experimental plot ; the measurements were made of five 

 hundred spores each on lea\cs and stems. The following results were obtained. 



