192 



MYCOLOGY 



pores and intercalary cells all have two nuclei, which are not sister 

 nuclei. The upper cell, cut off from the fusion cell, is the secio- 

 spore mother cell; the lower grows a little longer and then divides again 

 in the same way, and thus a vertical series of aeciospore mother cells is 

 formed, the oldest at the top. Each of the aeciospore mother cells. 



Fig. 66. — A, Chain of young jeciospores of Puccinia caricis; a, fusion tissue; 

 b, basal (fusion) cell with conjugate nuclei; c, asciospore mother-cell; d, intercalary 

 cell; e, young aeciospore; B, germinating teciospore of P. caricis; C, teliospore of P. 

 caricis; D, formation of teliospores of P. falcaria {after Dittschlag); E, development 

 of aecium {after Blackman) of Phragmidium violaceum; e, epidermal cell; s, sterile 

 cell; below these cells a nucleus is seen migrating into the adjacent cell /; F and G, 

 conjugation of two female cells to form basal cell of aeciospore chain {after Ditlschlog). 

 In G the first conjugate division is just completed. {Adapted frotn Grove, British 

 Rust Fungi.) 



as soon as it is formed, cuts off by conjugate division a small cell below, 

 called the intercalary cell; this sooA disorganizes and disappears, while 

 the other portion remains as the aeciospore. The succeeding uredinio- 

 spores have two nuclei in the conjugate condition and this is continued 

 over into the cells of the young teliospores (Figs. 67 and 68). Before 



