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 387 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, 1 go upon the 
evidence of Link, Kunze, Schott, Mettenius, and myself, 
who have had for many years under their observation ` 
lliving 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., 87, Soho Square, London; - 
| the “ Synopsis" by Hardwicke, 192, Piccadilly. 
