56 LINDSAY, ON AliKOTliALLUS. 



that we shall ultimately find the means of multiplication in 

 the lichens wonderfully varied, and not at all in accordance 

 with our preconceived notions, I consider it hazardous and 

 improper to doubt or depreciate the observations of any 

 botanist, and especially of men of such scientific eminence 

 as the gentlemen whose names 1 have enumerated. 



II. A. oxysjjoims. — I have already given so many details re- 

 garding the structure of -^. oxyspoi'us, in contrasting it with 

 A. Smithii, that little now remains for me to add. Kcirber says, 

 "Die librigen Abrothallus-Arten [besides^. Smit/til and A. 

 microsp.'] welche Tulasne nocli unterscheidet, aber in Deutsch- 

 land lusher noch niclit beobachtet zu sein scheinen, gelioren, 

 nach ihrem Sporencharacter, nicht in diese Gattung'^ (p. 216). 



I cannot regard the mere character of the spore to be a 

 sufficient reason for constituting species; else we should split 

 up the lichens into an endless number. A. Smithii and A. 

 oxysjioi'vs occur so constantly and intimately associated, the 

 mode of evolution and growth of the apothecia in both is so 

 precisely alike, and their apothecia are frequently so similar 

 in external appearance, that I must look upon them as per- 

 taining to one genus. The pycnides of the one, and the 

 spermogones of the other, also serve to distinguish them ; 

 but I think only as species. I cannot here omit a protest 

 against the unnecessarily and mischievously elaborate classi- 

 fication of Ki3i'ber, who, in his last pu])lication, enumerates in 

 Germany 136 genera, while I feel assured less than one third 

 would be found amply sufficient. It is this splitting up of 

 species and genera; this midtiplication of new and difficult 

 names; this complete changing of old familiar terms, that 

 operate as one of the most powerful barriers to the study of 

 lichenology. It is only, I am convinced, by simplifying the 

 science — by making genera and species as extensive as pos- 

 sible and thus diminishing names — by merging special pecu- 

 liarities in general laws, that we can hope to make licheno- 

 logy attractive. As a general rule, whenever A. Smithii 

 occurs, A. oxysporus may be looked for. In the majority of 

 cases, I found them growing together on the same thallus; 

 under Avhich circumstances it is very difficult to determine 

 to which species to refer the spcjmogones and pycnides 

 generally more or less plentifully intermixed. On Craigie 

 Hill, I met with both species abundantly. In other localities 

 the one or other predominated — e. g. A. oxysporus on Mon- 

 crieft'e Hill, and A. Smithii on Ben Lawers. The geogra- 

 phical distribution of the Abrothalli seems very irregular, 

 and is controlled by circumstances with which we are not 



