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POPULAR HISTORY OF LICHENS. 



rigid, and altered in form. R. farinacea differs from var. 

 calicaris only in the constant presence of soredia, and in the 

 smoother or more flattened character of the lacinise; we 

 look upon it as a sorediiferous form of this filiform variety 

 of R.fraxinea. The spores of this species are of medium 

 size, and easily recognizable ; they are somewhat oval-elon- 

 gated, rounded at the ends, straight or curved to various 

 degrees, bilocular or uniseptate, of a very pale yellow or 

 colourless. The young spore is oval and full of grumous 

 or finely granular protoplasm. In course of development 

 there appears at either end a globular aggregation of largish 

 granules, which increase in size, then disappear into a homo- 

 geneous mass ; this gradually acquires a membrane, and lastly 

 assumes the form and characters of one of the loculaments 

 or secondary cells of the spore. In the old state of the spore 

 these contained cellules again break up into a confused 

 granular mass ; and it is in this state also that the curved 

 form of the spore is most common. In all the species or 

 varieties of British Ramalinas which we have examined we 

 have found the spores having the same characters, differing 

 only in size, according to habitat. This we consider another 

 strong argument for the identity of species ; for, with Pries, 

 we are inclined to regard all the British Ramalinas as forms 



