306 



COMPARATIVE MORPHOLOGY OF FUNGI 



special perithecial wall, gradually reduced to a naked core. It seems 

 better to interpret the thyriothecia in the light of the pycnothecia and the 

 ascomata of Plectodiscella and to defer further conclusions until ontogenetic 



Fig 204 —Trichothyrium fimbriatum on Meliola. A. Upper surface of leaf showing 

 points of infection. B. The same enlarged. C. Periphery of mat. Some mycelium of 

 Meliola still visible in the middle. D, E. Hyphal bands. F, H. Formation of fructifica- 

 tions. I. Section of immature fructifications. J. Ascospores. (A X A A\ -» X 8; D to 1 

 X 285; J X 750; after Arnaud, 1918.) 



investigations of the Microthyriaceae are made. The actual striking 

 correspondence between the habit of Meliola and of the Microthyriaceae 

 would then be regarded as convergence phenomena. 



