XIV 
European Ferns. 
receding from the tropics, although with latitude, the species diminish in number, there is the 
same contrast between the two categories of climate — the dry continental type with a large, 
and the damp insular type with a small hiberno-aestival range.” 
The view taken of species in Mr. Baker’s comparative lists, like that in the “Synopsis 
Filicum,” is somewhat larger than that adopted by most writers ; but following it for purposes of 
comparison, we learn that only twenty-six species are found in the Arctic zone, of which 
all but two, Athyrium crenatum, and Aspidium fragrans, are natives of Britain. Tropical 
America and tropical Asia — the latter including the Polynesian islands — are the two 
richest regions in ferns. In tropical Asia there are eight hundred and sixty-three species, 
of which four hundred and seventy-seven are peculiar to that region, while tropical America 
has nine hundred and forty-six species, seven hundred and eight of which do not occur 
elsewhere. Of course this estimate is slightly below the actual number of ferns at present 
known, more than ten years having elapsed since its publication ; but the numbers 
are relatively correct. One remarkable feature connected with the distribution of ferns 
is the large proportion they bear in the vegetation of some of the African islands. Thus 
in the Mascarene Archipelago — understanding by this term the islands of Madagascar, 
Mauritius, Bourbon, and the Comoros — there are more than two hundred species of ferns, 
more than double the number of the most fully represented order of flowering plants, i.e., 
the Orchidaceae ; while there is reason to believe that, in Madagascar, at any rate, 
many ferns have yet to be discovered, as recent collectors have quite lately added several 
species to the list. In the little island of Tristan d’Acunha, the proportion of ferns to 
flowering plants is remarkably large, there being no less than twenty-three of the former 
to twenty-nine of the latter. St. Helena comes next of known floras to Tristan d’Acunha, 
in the proportion which ferns bear to phanerogamia, which is nearly as two to three, and 
it is very remarkable from the fact that half of them are peculiar to it. 
Among the European ferns there are some which do not extend beyond the continent ; 
these are, Hymenophyllum Wilsoni, Asplenium germanicum, A. Heuffleri, A. Petrarchae, 
A. fissum, A. Seelosii, Cystopteris alpina, C. sudetica, and Cheilanthes hispanica, the two 
first being British species. Aspidium asmulum and Davallia canariensis are only a little less 
restricted in their range, the former (which in Europe is confined to Britain) occurring also 
in Madeira and the Azores, while the latter is confined to Spain and Portugal, and the islands 
of Madeira and Teneriffe. 
Ferns reach their maximum concentration in tropical America, “amongst the dripping 
rocks of the higher level of the Andes, the forests of their slopes and ravines, and the 
dense humid flats that border the innumerable branches of the Amazon, where the sun’s 
rays and the wind never penetrate the recesses of the primeval jungles, and climbers and 
parasites contest with the leaves of bright flowering trees for the possession of the 
branches.” About nine hundred and fifty species are found in this region, constituting 
forty-two per cent, of all known ferns, and more than three out of four are quite peculiar 
to it. For tropical Asia and Polynesia, eight hundred and sixty-three species were on record 
at the date of Mr. Baker’s paper, of which four hundred and seventy-seven are peculiar 
to the district ; the Polynesian list containing three hundred and eighty species, of which a 
hundred and fifty are peculiar. In tropical Arabia we have a million square miles “almost 
a blank, so far as ferns are concerned.” The fern-flora of tropical Africa (including the 
islands of the Mascarene group) has three hundred and forty-six species, of which a hundred and 
twenty-seven arc peculiar. South temperate America yields only a hundred and eighteen 
