50 LINDSAY, ON ABROTIIALLUS. 



or occasionally depressed. This ostiole is^ however, gene- 

 rally larger and more prominent than that of the spermo- 

 gones, and its edges more frequently swollen and raised. 

 Sometimes — as in specimens of A. Smithii ft-om Glen Shee 

 and Glen Beg— the pycnides are supei^icial, and prominent, 

 forming rough, tubercidated, black warts, seated on the sur- 

 face of the thallus, each pierced by a distinct pore. The 

 body of the pycnidis is immersed, spherical, and enclosed in 

 a brown cellular tissue. When moistened, the pycnides 

 appear as brown translucent spots, precisely like the sper- 

 mogones. Tulasne says that tlie pycnides of A. Smithii 

 are " interdum copiosissiraae, imo apotheciis multo frc- 

 quentiores," especially when they occur on Parmelia tiliacea; 

 he also describes those of A. microspermus as abundant; but 

 of A. Wehvitzschii, he remarks, " Pycnides desiderantur.^' 

 I have found the pycnides indiscriminately associated with 

 varieties a and ft, and am convinced that the description of 

 the pycnides of his species A. Smithii applies equally 

 to those of his A. Welivitzschii. I have never, however, 

 noticed pycnides so abundantly distributed as Tulasne would 

 seem to imply. I have seen an intermixture of spermogones 

 with young apothecia in A. oxysporus, associated on the same 

 squamule with A. Smithii, " interdum copiosissimge ; " and it 

 appears to me possible, from the great resemblance, that 

 Tulasne may have hurriedly overlooked the distinction 

 between them, more particularly as he speaks of the " sper- 

 mogonise ignot?e " of the genus Abrothallus. 1 have most 

 frequently found the best specimens of pycnides scatteretl, 

 to the number of four or six, near the margin of sterile 

 squamules, Avhich had a leaden or grayish hue, and were 

 thickened, corrugated, and warted. While the other cha- 

 racters are similar, the pycnides differ remarkably fi'om the 

 spermogones in containing styJosjJores, instead of spermatia. 

 These are cellular bodies, having much the appearance of 

 certain spores, about ^^'^,7 to ^-jo "^^h long, by -jj'gjy to ^ (j^ojj 

 broad. They are normally pyriform or obovate; but they 

 are sometimes spherical, oval, oblong, navicular, fusiform, 

 or present irregvdar bulgings. These abnormalities of form 

 generally occur in Highland specimens. Viewed in different 

 lights, they may be colourless or of a pale yellow tinge; 

 sometimes the contained globules were pale yellow ; at other 

 times the whole stylospore was of a distinct yellow. In 

 the latter case, in Highland specimens, the stylospores were 

 generally small and shrivelled. With regard to their con- 

 tents, Tulasne remarks, " Nimc protoplasma subliquidum 

 fereque homogeneum, nunc guttulas oleosas 2 — 3 fovent,'' 



