224 



THE ASCOAIYCETES 



culture. The genus is therefore well adapted to cytologic and 

 genetic studies, matters on which essentially nothing is at present 

 known. 



Fig. 88. Structure of Gloinerella glycmes. A. Diagram of three perithecia 

 borne innately on dead stems of soybean. B. Ascus. C. Germinating 

 ascospores with resultant formation of appressoria. D. Conidia (Colleto- 

 trichinn glycines) from pustules on living pods and stems. E. Appressoria 

 formed from germinating conidia. F. Infection from conidium. The in- 

 fection hypha penetrates the host cell wall by a narrow tube formed 



immediately below the appressorium. 



DiAPORTHACEAE. The Diapotthaceac comprise a group of over 

 1000 species of stromatic Sphaeriales. Most of them are sapro- 

 phytic, but in this family is Endothia parasitica, ^\ hich, within 

 a period of about 30 years, spread throughout the entire Appa- 

 lachian region and practically accomplished the extinction of 



