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POPULAR HISTORY OF LICHENS. 



our Highland mountains, such as Ben Lomond and Ben 

 Lawers. As in PeMigera, the cells of the vegetative system - 

 are very large and distinct. The thecse are large, elongated, 

 and eight-spored; the spores are large, broadly ellipsoid, 

 brownish, bilocular or uniseptate, closely packed spirally. 

 Prom their size and distinctness, this is a good species in 

 which to study the thecse, spores, and paraphyses. 



2. Solorina saccata {saccus, a bag or pouch). Thallus, 

 above bright green, becoming, when dry, greenish-grey, 

 — below white and fibrillose-gibbous ; apothecia blackish- 

 brown, at first appressed, then depressed and saccate. 



A less elegant and less common species, growing on earth 

 in the fissures of damp and shady rocks in various parts of 

 the Highlands. The peculiar bagged or saccate character of 

 the fructification is well seen only in old plants. Its spores 

 are thick-walled, broadly ellipsoid or oval-oblong, bilocular, 

 and of a deep brownish tint ; they are remarkable in being 

 externally punctate-granulose. In germinating, they send 

 from both extremities a colourless filament, — proceeding 

 from the endospores, — which gradually becomes elongated 

 and very ramose. 



