182 PROCEEDINGS OF THE AMERICAN ACADEMY 



A. E. Eaton, of the British Transit Expedition, and determined by 

 Dr. Nylander, was publi.<hed by tlie Rev. J. M. Crombie in the "Jour- 

 nal of Botany," and was followed by a full enumeration of Mr. Eaton's 

 lichens by the same gentleman, with tlie same assistance, in the '• Jour- 

 nal of the London Linnaean Society, Vol. XV. ; as now, at length, by 

 a " Revision of the Kerguelen Lichens collected by Dr. Hooker," in 

 the "Journal of Botany," for April, 1877. The naturalist of the Brit- 

 ish expedition had much better luck m collecting, amid the countless 

 discouragements of the " island of desolation," or was less embarrassed 

 by other and higher branches of natural history, than ours ; and Messrs. 

 Nylander and Ci-ombie have tiius been able to largely extend this cu- 

 rious lichen-flora ; while a comparison with Dr. Hooker's specimens 

 (very few, indeed, of which could be discovered in the herbarium of 

 Dr. Taylor) has enabled them to determine some of the latter writer's 

 new species, fbc the determination of which his own descriptions were 

 entirely inadequate. There is also something over a page, in Mr. 

 Crombie's last paper, of observations on the present writer's list of 

 Kerguelen lichens above mentioned, upon which it will be proper to 

 make some remarks. 



And first as to what is called the unfortunate " neglect of the chemi- 

 cal reactions," which, it is said, renders the " diagnosis incomplete, and 

 so far uncertain." This is simply a matter of opinion. I studied the 

 question of the use of certain chemicals in the systematic investigation 

 of lichens, witli such care as I could give it, ten years ago, and have 

 since seen no reason to change the view then expressed (Amer. Natu- 

 ralist, April, 1868). The application to the lichen-tissues of the tests 

 used is not without interest, and may give results of some utility, so far 

 at least as they go ; but this quantum vidctar impedes every stage of 

 the inquiry, and the unequivocal value assumed for the results has 

 never been any thing but an assumption. And opinions may also differ 

 as to the value of the chemical "species" which have resulted from the 

 " reactions." Dr. Nylander has remarked of one of these species, his 

 Parmelia cetrarioides, that it scarcely differs from another except chemi- 

 cally, — " vix differt nisi reactione. . . . a P. oUvetorum : at distin- 

 guenda est nomine propria, Jam earn ob causam" (Nyl. Obs. Lich. Pyr. 

 Orient, p. i 6), and his remark is applicable to not a few others, whether 

 or not now appearing to be supported by secondary lichen-characters. 

 I decline, for my part, to receive such species. And there can be no 

 doubt that the tendency of this scrutiny of " the reactions," as of another 

 now far from unknown method <.f study, — the scrutiny, that is, of minute 

 and not seldom unimportant differences of all sorts, to the ignoring, for 



