3G8 Transactions. — Botany. 



tliis variety of St. condensatum, where the apothecia do not betray the slightest 

 traces of stipites, and which, in tlie absence of intermediate states, I am 

 strongly inclined to elevate to the rank of a species, more especially as the 

 spores are shorter and thicker than any belonging to this species hitherto seen. 



In St. strictum, Bab., as well as in one or two others, are seen spores, very 

 much resembling those of the present lichen, although not more than half 

 their length. The reactions by means of iodine on the hymeneal gelatine also 

 correspond generally to those seen in species of the same genus. 



The relationship of this lichen to Bceomyces is less obvious, and, but for 

 Dr. Nylander's assertion, (Synop. p. 175) and a certain prima facie resemblance, 

 I would not have mentioned this genus as analogous, indeed in the light of the 

 present plant I can assert, with considerable confidence, that Gomjihillus has 

 much stronger affinities to Stereocaidon than to Bceomyces. 



In plants such as the present it is extremely foolish to dogmatize in the 

 matter of classification, and we are taught the lesson that nature is not to be 

 cramped and confined by any such well defined limits as our modern classifiers 

 would fain lead us to believe. 



Stereocaulon buchanani, Strn. 



Thallus tenuis efiusus, cinerascens vel cinereo-virescens, e gonidiis 

 conglomeratis mediocribus et filamentis irregularibus, fere omnino constans ; 

 apothecia majuscula (latit. 1-2 millim.), sessilia vel elevato-sessilia, interdum 

 conglomerata, fusca (junioribus pallidis et nonnihil turbinatis), convexa et 

 immarginata, intus fuscescentia, textura tenaci cornea. Sporce Snse, in thecis 

 cylindricis, longissimse, filiformes, 40-50-septat?e, longit. 0-16-0'22 millim., 

 crassit. circa 0-003-0"004: millim. ; paraphyses hand distinctpe. Gelatina 

 hymenialis iodo leviter cserulescens (apicibus thecarum intensius tinctis) dein 

 rufescens. 



Thallus thin granular cinerascent or cinereo-virescent effuse, composed 

 almost entirely of conglomerated gonidia of a medium size and an irregular 

 fibrous stroma ; apothecia rather above average sessile or elevato-sessile fuscous, 

 in a younger state much paler and then somewhat turbinate, convex and 

 immarginate, fuscescent within and of a tenacious horny texture ; si)ores 8, in 

 cylindrical asci, very long and filiform, 40-50-septate, and measuring 0-1 0-0*22 

 by 0-003-0- 004 of a millim., paraphyses not distinct. Hymeneal gelatine slightly 

 crerulescent with iodine, the apices of the asci more deeply tinted, the whole 

 assuming afterwards a rufoscent tint. 



Notes on Stereocaulon buchanani, Stirton. 

 By Charles Knight, F.R.C.S., F.L.S. 

 The valuable report of Dr. Stirton on Buchanan's plant has been bronght 



