EX TO MOP 11 THOKA LES 



287 



phytes. Another species studied in recent years in America by 

 Gilbert (1919: 263) and Martin (1925 6: 311), and described by 

 the latter writer as C. villosus INIartin, was isolated from fern 

 prothallia and from rotting wood bearing a species of Hypochnus. 

 It grows readily on artificial media. 



Sexual spores are known only in C. utriculosus. Here a pair 

 of projections arising from two hyphal bodies enlarge terminally. 



Fig. 103. — Conidioholus villosus Martin, (a-rf) Stages in germination of 



conidium and formation of secondary conidium. (e, /) Transformation of 



conidium into an appendaged resting spore, {g) Resting spore shrunken to 

 oval form, {h) Germination of resting spore. {After Martin 1925.) 



These apical swellings, which are very unequal in size, come in 

 contact and conjugate, the intervening walls being broken down. 

 The contents of the two cells merge, and a large, thick-walled 

 spore is formed in one of the cells. Brefeld regarded the process 

 as distinctly oomycetous in nature, but Thaxter feels that the 

 spore is clearly a zygospore. In C. villosus (Fig. 103) the direct 

 transformation of mature conidia into characteristically append- 

 aged resting spores is described by Martin. 



