UREDINALES 



565 



Fig. 378. — Cronartium ribicola. Development of uredinium 1. Fundament, of sorus 

 and stoma. 2. Older stage. 3. Mature sorus. P, peridial cell; Sp, young urediniospore; 

 St, stalk cell; B, basal cell; A, multinucleate basal cell before the formation of the uredinio- 

 spore mother cell, C; D, spore and stalk cell just formed from urediniospore mother cell; 

 U, mature urediniospore; E, crushed epidermal cells. (X 330; after Colley, 1918.) 



Fig. 379. — Phragmidium Rubi. 1. Periphery of uredinium. P, paraphyses. Puc- 

 cinia glumarum. 2. Uredinial mycelium in host tissue. (1 X 565; 2 X 830; after Sappin- 

 Trouffy, 1896, and Lindfors, 1924.) 



