170 SEXUAL REPRODUCTION IN THE MUCORINI. 



Daring gormi nation this coat sensibly loses its thickness. The 

 interior utricle, which is thin, then swells, and bursts its two enve- 

 lopes in order to elongate into an upright tube of uniform diameter, 

 and which remains simple. This tube is obtuse, and at first con- 

 tinuous, but it finally exhibits some transverse partitions, especially 

 towards its base, and it swells at its summit into a large globular 

 conceptacle filled with spores identical with those of the adult and 

 perfect plant. It does not appear that the zygospores directly 

 produce a mycelium, at least we have not observed that they emit 

 any branches at their base. Similar things take place in the ger- 

 mination of the zygospores of Mucor Syzygites, as M. M. Schacht 

 and de Bary have reported. From this fact it would result that the 

 zygospores of the Mucorhii represent a life incapable of being continued 

 without change of form, at least in the first generation, and that 

 the Mucors possess at least two alternating modes of reproduc- 

 tion. 



ON THE BARER LICHENS OF BLAIR ATHOLE. 



By the Rev. J. M. Crombie, M.A., F.L.S. 



The district of Blair Athole occupies the N.W. portion of the 

 Highlands of Perthshire, and is traversed by the central chain of 

 the Grampians. Though a few species of lichens appear in some 

 of the older British Herbaria from Ben-y-gloe, the highest ridge of 

 mountains in the district, yet it would not appear until recently 

 to have been systematically explored by any lichenist. The fol- 

 lowing record of the rarer species — many of them new to science, 

 and others elsewhere extremely rare in Great Britain and Ireland 

 — which I collected during a few weeks spent in the district in the 

 autumns of 1870-1, will suffice to show how rich it is in this class 

 of our Cryptogamic Flora. The majority, as will be seen, are from 

 three localities, viz. — Craig Tulloch, a low-lying hill south of the 

 village of Blair, some 900 feet high ; Cairn Gowar, the loftiest 

 of the Ben-y-gloe mountains, 3,690 feet in height ; and from Glen 

 Fender, N.W. of the village, and about half way between the two 

 preceding. 



1. Pyrenopsis fuscatula. Nyl. — Very sparingly on a quartzose 

 boulder, in a stream on Cairn Gowar. 



2. P. lecanopsoides. Nyl. — Very rare on moist calcareous rocks 

 of Craig Tulloch, with the spores but seldom well developed. 



3. P. Scheererii. (Mass.) Here and on dry calcareous rocks of 

 Craig Tulloch, with both thallus and apothecia very well developed. 



4. Collema auriculatum. rar. pinguescens. Nyl.- " Thallus 

 thicker, lobes more divided." Rather scarce, on shady calcareous 

 rocks of Craig Tulloch, amongst decayed mosses. 



