iqiq] 



KEMPTON—P YCNIDIUM 



253 



from peony, Voliitella Jructi, and Volutella circinans; it also is at 

 times observed in the development of isolated sporodochia of 

 Patellina fragariae. This mode is more seldom found than either 

 the compound meristogenous or symphogenous method in the 

 development of acervuli and sporodochia. 



TABLE II 



The species of Pestalozzia studied present a type of sporing 

 structure which is in need of further investigation in other genera 

 and species. From the mature structure it has been classed as an 

 acervulus, but from its origin and development it is not a true 

 acervulus, for it arises as a pycnidium and opens to form an acer- 

 vulus when mature. This may be called a pseudo-acervulus. 



According to Potebnia (30) and Diedicke (id), some species 

 of Septoria and Ascochyta have open-topped sporing bodies 

 arising by the interweaving of hyphae to form a bed from which 

 arises a peridium partially surrounding the inner sporing surface. 

 Such a structure is designated by Potebnia as a pseudo-pycnidium. 



Study of the origin and development of the sporing bodies of 

 the many genera and species of the Sphaeropsidales and Melan- 

 coniales which have not yet been investigated will no doubt add to 

 these 2 types. 



In the pycnidia-bearing fungi studied the meristogenous method 

 of development is the more prevalent, the symphogenous type 

 seldom appearing. In species forming acervuli and sporodochia, 



