ON GENERA AND SPECIES. 59 



tinct species may be doubted by some Pteridologists ; but 

 be that as it may, there can be no doubt but that the 

 " Species Filicum " and " Synopsis " are highly valuable 

 to students of Ferns,* possessing- herbaria or cultivated 

 collections, as also to travellers abroad. 



I have now to notice another important work by 

 Mr. Baker, published in 1870, namely, that part of 

 Martius's " Flora of Brazil," containing the Ferns ; a folio 

 work of 317 pages, with fifty plates, each plate containing 

 many figures of portions of fronds, showing the differential 

 characters of the genera and species. Of the latter there 

 are 887 described, the genera being arranged in the same 

 order as in the " Synopsis Filicum." On taking into consi- 

 deration the extensive territory of Brazil with its various 

 climates favourable to the growth of Ferns, from those 

 growing at elevations that may be termed sub-arctic, to 

 others luxuriating in the lower hot valleys and rocky or 

 forest ravines, the number of 380 species may be con- 

 sidered small ; but here again comes the question, what is 

 a species ? and judging from Mr. Baker's view, it would 

 appear that many plants originally described as species, 

 which successive authors have acknowledged to be distinct, 

 are, nevertheless, in many cases regarded as synonyms ; 

 thus Ferns long accepted by previous pteridologists cease 

 to be so. When I say long accepted, I go upon the 

 evidence of Link, Kunze, Schott, Mettenius, and myself, 

 who have had for many years under their observation 

 living examples of species all well recognised as being 

 different from one another by some important characters 

 seen only in the living state, but Mr. Baker, with herba- 

 rium specimens, makes no scruple of lumping many of such 



* The first published by Dulau and Co., 37, Soho Square, London ; 

 the "Synopsis" by Hardwicke, 192, Piccadilly. 



