124 



FUNGI. 



of short threads, either enclosed in a perithecium, or seated upon 

 a kind of stroma. These are exceedingly variable, sometimes 

 large, and multiseptate, at other times minute, resembling sper- 

 matia. In such genera as are chiefly epiphytal, in Septoria, 

 Phyllosticta, and their allies, the minute spores are enclosed 

 within membranaceous perithecia, and when mature these are 

 ejected from the orifice at the apex, or are exposed by the break- 

 ing off' of the upper portion of the perithecia. In Diplodia and 

 Hendersonia the spores are larger, mostly coloured, often very 



fine in the latter genus, 

 and multiseptate, escaping 

 from the perithecia by a 

 terminal pore. Probably 

 the species are only pyc- 

 nidia of Sphariacei, but 

 that is of no consequence 

 in relation to our present 

 inquiry. Of stylospores 

 which deserve mention on 



FIG. 49.-Spore of Hen- FIG. 50.-Spores of Dllo- account of their singU- 

 dergonia potycystw. phospora graminis. ] ar ity o f form, W6 may 



note those of Dilophospora graminis, which are straight, arid 

 have two or three hair-like appendages at each extremity. In 

 Discosia there is a single oblique bristle at each end, or at 

 the side of the septate spores, whilst in Neottiospora a tuft of 



FIG. 51. Spores of Discosia. FIG. 52. Spore of Prosthemium betulinum. 



delicate hairs is found at one extremity only. The appendages 

 in Dinemasporium are similar to those of Discosia. The spores 



