THE SPORE AND ITS DISSEMINATION. 



135 



posed, in which the sporidium (as in Perisporium vulgar e) 

 consists of four coloured ovate joints, which ultimately separate. 

 Multiseptate fenestrate sporidia are not uncommon in Oucurlii- 



FIG. 75.-Spoiidia of 

 Valsa taleola. x 400. 



Fio. 76. Spori- 

 dium of Sjjorormia 

 intermedia. 



FIG. 77 



taria and Pleospora, as well as in Valsa fenestrata and some other 

 species. In the North American Sphtfria putaminum the sporidia 

 are extraordinarily large. 



The dissemination of the sporidia 

 may, from identity of structure in the 

 perithecium, be deemed to follow alike 

 method in all. When mature, they are 

 in a great measure expelled from the 

 mouth of the perithecia, as is evident 

 in species with large dark sporidia, 

 such as exist in the genera Hypoxylon, 

 Melanconis, and Massaria. In these 

 genera the sporidia, on maturity, may 

 be observed blackening the matrix 

 round the mouths of the perithecia. 

 As moisture has an evident effect in producing an expul- 



FIG. 78. Sporidium of Sphceria 

 putaminum. x 400. 



