360 BROOKLYN BOTANIC GARDEN MEMOIRS 



Avenae, infected Secale cereale as well as Ave^ia sativa. Eriksson, 

 however, gives no information regarding the infecting capacity of 

 uredospores from the four grasses mentioned. 



Jaczewski (68) made fairly complete tests with aecidiospores from 

 the barberry, obtained by inoculation with teleutospores from various 

 gramineous hosts. He records exact correspondence between the 

 results obtained with the aecidiospores and uredospores from the 

 grasses used as a source for the teleutosporic infections of the barberry. 



Pritchard (no) found that aecidiospores from barberry in the open 

 infected Avena sativa, A.fatua, Agropyron tenerum, A. repens, Hordeum 

 jubatum and Secale cereale, but not Hordeum vulgare nor Triticum vul- 

 gare. They thus correspond to the infecting capacity of uredospores 

 from the gramineous hosts. 



Stakman's (143) results are in harmony with those mentioned. In 

 one trial, the barberry was infected with teleutospores from wheat, 

 although standing in the open. The aecidiospores, when inoculated 

 onto various plants, 'infected the following: wheat, barley, oats, rye 

 and Triticum monococcum. In another test, aecidiospores from the 

 barberry, produced by inoculation with teleutospores from Agropyron 

 repens, infected wheat, barley, and rye, but not oats, while a similar 

 series, starting with teleutospores from wheat, infected wheat, barley, 

 rye, but not oats. These results are in close correspondence to those 

 previously mentioned for uredospores. 



Arthur (7, 8, 10) has infected the barberry with teleutospores from 

 Agrostis alba; the aecidiospores produced infected Hordeum vidgare 

 and Triticum vulgare but not Avena sativa. Teleutospores from 

 Elymiis canadensis also infected the barberry but the aecidiospores 

 developed failed to infect Secale cereale and Triticum vulgare. Other 

 results of Arthur are the following: aecidiospores from barberry, 

 arising from inoculation with teleutospores from Agropyron tenerum, 

 infected Avena sativa and aecidiospores, arising from inoculation with 

 teleutospores from Sitanion longifolium, infected Triticum vulgare. 



Freeman and Johnson (57) studied the variations in tlie size and 

 shape of the uredospores of the different races. While the uredospores 

 of the same race varied considerably in these points, yet they found 

 well-defined differences in the uredospores of the various races. 

 Stakman and Piemeisel have made similar studies and confirm the 

 conclusions of Freeman and Johnson. 



Puccinia coronata Corda. Next to Puccinia graminis the crown 

 rust of grasses has been the most extensively investigated rust from 

 the standpoint of its heteroecism and its restriction to hosts. De- 

 Bary (17) first established the fact that the aecidial stage of a crown 

 rust on grasses occurred on Rhamnus. Plowright (108) seems to have 



