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 scio- 

 spore mother cell; the lower grows a httle 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 seciospore mother cells, 



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

 b, basal (fusion) cell with conjugate nuclei; t, seciospore mother-cell; d, intercalary 

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

 caricis; D, formation of teliospores of P. falcarice (after Ditlscklag); E, development 

 of aecium (after Blackman) of Phragmidium violaceum; e, epidermal cell; i, 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 seciospore chain (after Dittschlog) . 

 In G the first conjugate division is just completed. (Adapted from Grove, British 

 Rust Fungi.) 



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

 called the intercalary cell ; this soon 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 



