VIII] 



UREDINALES 



203 



Fig. 1 76. Puccinia Graminis Pers. ; a. infected leaf of Berberis vulgaris, 

 nat. size ; b. group of aecidia, x 5. Uromyces Poae Rabenh. ; c. 

 infected leaf of Ranunculus jicaria, nat. size ; d. group of aecidia, 

 X2o; E. J. Welsford del. 



mother-cell (fig. 178). The spore mother-cell divides in the usual way, 

 separating the aecidiospore above from its sister-cell below, but the latter 

 here forms an elongated stalk instead of an intercalary cell. Each outgrowth 

 of the basal cell thus produces only a single spore, the mode of formation 

 of which is exactly similar to that of a uredospore. The fructification has 

 generally been regarded as a uredosorus and is known as the primary 

 uredosorus, in reference to its appearance relatively early in the season. 



Fig. 177. Puccinia Falcariae; branched 

 fertile cell of aecidium or primary 

 uredosorus, x 1200; after Dittschlag. 



Fig. 178. Phragmidium Potcnlillae-Canadensts 

 Diet.; a. conjugation; b. branched fertile 

 cell ; after Christman. 



