326 



[Vol. 2 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



posites, the highest 

 world. 



f phyletic evolution in the plant 



In conclusion, the Ascomycetes present a very rich 7 

 of form, structure, and adaptation with very marked di\ 

 series. Some of these 

 sion from 



present evido 



of prog 



sim 



generalized forms to highly specialized 



forms, while others indicate descent by reduction, 

 dences of progression are of the same kind and val 

 generally recognized in other groups of plants. 



Sachs, in his later 

 agreed with deBary 

 nizing the Ascomyc 



The 



as a 



ith an as- 



distinct phylum, \ 

 cending series fr 

 and generalized forms to com 



sim 



and specialized 



He 



Fig 4. Gymnoascus Recssii: A-D, neve r mentioned the tricho 



formation of sexual organs, fusing at C; 



E, sexual organs in uninucleate condi- SY ne &S evidence of their phy 



tion; F, fusing sexual organs in multi- 

 nucleate stage. — After Dale. 



letic relation to the red al^ 

 But his theory was based 



the presence of a procarp whether with or without a tricho- 

 gyne. He selected Gymnoascus, where the sexual apparatus 

 consists of simnle copulating gametangia, as the simplest 



ascomycete known at that time. It 



years 



that the trichogyne has been seized upon as evidence of the 



phyletic relation of the tw 





roups and has forced this 



anomalous backward reading of the history 



Part II. Elucidation 



NOTE I 



The red algae are remarkable for the great constancy in the 



form of 



branch, carpogonial branch 



etc.) and the very great divergence in the 



subse 



quent to the fertilization of the egg (terminal cell of the pro- 

 carp, carpogonium) and ending in the production of the carpo- 

 spores. The general character of this divergence may be 

 shown by a brief presentation of several tvpes. as follows : 



