LA BO ULBENIALES 



377 



asci or first divide longitudinally (Fig. 252, 5). The fundament of the 

 asci develops by a conjugate division of the ascogenous cells; a daughter 

 pair migrates into the young ascus, the other daughter pair remains in the 

 ascogenous cells. This process is repeated (Fig. 252, 5). The fusion of 

 the carpogenic cell and trichophoric cells probably is a plasmogamy similar 

 to that of Poly stigma rubrum. 



Of other differences between the Laboulbeniales so far known and the 

 Stigmatomyces type, only the variation in number of ascogenous cells 

 will be mentioned. While there are four in Stigmatomyces and two in 



myces 



inset 



Htncro- 

 X 200, 



Laboulbenia, there is only one in Amorphomyces, and in Polyascomyces 

 about thirty-two ; in the latter the ascogenous cells form a sort of placenta 

 from which the asci develop. 



Peyritschiellaceae. — In this family the antheridial cells have united 

 into a specialized organ and do not discharge their spermatia directly from 

 their opening, but extrude them into a common cavity from which they are 

 liberated (Fig. 253, 2 to 7), hence they are called compound antheridia. 



This family contains about 25 genera, some of them very large, and 

 seems to reach the height of its development in the tropics. 



Rickia may be taken as an example of the Peyritschiellaceae with a 

 highly developed and variable receptacle. While the axis is often simple, 



