May 22, 1916 



Hypoderma Dejormans 



279 



Pressure within the apothecium on approaching maturity, together with 

 the elongation of the central elements, causes the rupture to occur on this 

 line. After initiating the line of rupture, the filaments disappear and no 

 sign of their presence exists when the spores are mature. In all material 

 so far examined this mechanism is a constant characteristic. Where 

 two apothecia are formed side by side, the filamentous structures are in 

 marked contrast to the division line between the two apothecia as 

 formed by the union of the darker colored elements of the apothecial 

 covering. Von Tubeuf found in Hypoderma strobicola Tub. (Lopho- 



if. 



T 



mm 



FIG. 2. Asci, spores, and paraphyses of Hypoderma deformans. 



dermium brachysporum Rostr.) the same structure which he describes for 

 Lophodermium pinastri (Schrad.), but no such structures were found in 

 H. deformans. 



Apothecia with mature spores (fig. 3) may be found at any season of 

 the year. This is due to the fact that the spores do not ripen or are 

 not all freed simultaneously when the split first appears in the apothecium. 

 The process of spore liberation is observed to extend over a long period 

 of time. A year may elapse before the apothecia have entirely liberated 

 their spores. During periods of drought the medial slit in the apothe- 

 cial covering remains closed, only opening on the return of abundant 



