6 The North American Cup-Fungi 



media produced layers of sclerotized tissue with scattered scle- 

 rotia. From this crust-hke growth so called receptive bodies are 

 formed which are more or less columnar and about 1 mm. in 

 height. These structures when spermatized with microconidia 

 from another thallus finally produce mature apothecia. The 

 receptive bodies of each isolate do not, however, react with 

 their own microconidia. 



Heterothallism 



While from the above we appear to have a condition of 

 heterothallism in Sderotinia Gladioli, Drayton (M>-cologia 26: 

 69. 1934) believes that while this is in a sense heterothallism, it 

 is not true heterothallism as the term is usually understood 

 since while microconidia and receptive bodies must be produced 

 on different thalli, these may have arisen from a single hyphal 

 tip, while in true heterothallism the series are segregated on 

 different thalli. However, the term heterothallism is used 

 differently by the various authors and there is a chance for a 

 difference of opinion on this point. 



