152 NYLANDER ON THE ALGO-LICHEN HYPOTHESIS, &C. 



chemical characters are entirely similar, and of similar value with 

 the other characters ; all are auxiliary, but the former excelling in 

 simplicity and perspicuity, are at the same time very easy and 

 necessary. Accordingly in the present state of Lichenography, 

 we may not neglect them, or if we do neglect them, the whole of 

 Lichenography would become worthless and profitless. But it is of 

 the greatest importance that those as well as the other characters 

 should be rightly and accurately observed ; for, if badly and un- 

 skilfully employed, they lead to errors ; as happens through any 

 defect of dexterity and sound judgment in matters relating to 

 science, and nowhere is expertness and judgment more necessary. 



In p. 16, we read, " I have seen in some apothecia of this variety, 

 or of the following, the normal spores of Lecanora subfusca replaced 

 by the spores in equal number of an entirely distinct physiognomy 

 — spores twice as large, brown, 1-septate, without apparent change 

 in the other portions of the apothecium. M. Nylander, to whom I 

 submitted pieces, has hesitated to pronounce upon the possible 

 causes of such an anomaly." Here the experience of the author 

 by no means shines forth. He had, indeed, submitted to me hete- 

 rogeneous apothecia, growing mixed with the apothecia of a certain 

 " Lecanora subfusca" saying on a label, " apothecia L. subfusca?., 

 bearing different spores (brown, 1-septate)," an absurdity unworthy 

 of any lichen whatever, or any other plant. I answered, "this 

 is something marvellous ; I have known nothing so prodigious." 

 This the author does not seem to have understood, nor very faith- 

 fully rendered. " Nylander has hesitated, &c," when on a more 

 attentive examination, the wonderful knot could easily be solved. 

 Manifestly it relates to two lichens occurring conjointly, as is every 

 day seen, with the thalli so intermingled that the different apothecia 

 appear as if sitting on the same thallus.* Examining to-day those 

 apothecia which were sent, it was at once evident that the apothecia 

 with the brown spores belonged to Physcia aipolia. Accordingly, 

 Lecanora subfusca was growing mixed with this Physcia, which was 

 the " wonder." It may be added that, in no respect, either external 

 or anatomical, do the apothecia of both present any likeness. f 



* This is equally the case, and perhaps even more frequently so with the 

 spermogones, which it cannot be doubted are as constant in their chai'acter in the 

 different species as are the apothecia. Inattention to this has led Dr. Lindsay to 

 propound his very erroneous theory of the " Polymorphism of Spermogones." — 

 J. M. C. 



f It may be observed that lichens occurring without any thallus, or as para- 

 sites of other lichens, are of a very low order; the inferior Lecidece (nearly Patel- 

 larice, scarcely any Biatora), Opegraphce, Artlwnice, Melaspilece, Yerrucarice, 

 Endococci, Mycopora. Some Biatora 1 , which seem to occur as parasites, and as if 

 athalline, yet are not entirely destitute of traces of a thallus (thus, for instance, 

 gonidia are observed amongst the apothecia of Lecidea Heerii, Hepp., on the 

 tLallus of Peltigera (Nyl., in my copy.) I may here notice also that Lecanora 

 sophodes, var. pictavia, Wedd., p. 17, is certainly nothing new. Elsewhere I 

 may adduce the names formerly received. 



