CHAP. X.] 
THE PAL.EARCTIC REGION, 
207 
fiud that they are of Palsearctic genera and, with one exception, 
all of species found either in Europe, North Africa, Madeira, 
or the Canaries. The exception is a bullfinch peculiar to the 
islands, but closely allied to a European species. Of land birds 
there are twenty-two, belonging to twenty-one genera, all Euro- 
pean. These genera are Cerchneis , Buteo , Asia, Strix, Turdus , 
Oriolus, Erithacus, Sylvia , Regulus, Saxicola, Motacilla, Plec- 
trophanes , Fringilla , Pyrrhula , Serinus , Sturmis , Pious , 
Upupa, Columba, Caccabis, and Coturnix. Besides the bull- 
finch {Pyrrhula) other species show slight differences from their 
European allies, but not such as to render them more than 
varieties. The only truly indigenous mammal is a bat of a 
European species. Nine butterflies inhabit the Azores; eight 
of them are European species, one North American. Of beetles 
212 have been collected, of which no less than 175 are Euro- 
pean species ; of the remainder, nineteen are found in the 
Canaries or Madeira, three in South America, while fourteen 
are peculiar to the islands. 
Now these facts (for which we are indebted to Mr. Godman’s 
Natural History of the Azores) are both unexpected and exceed- 
ingly instructive. In most other cases of remote Oceanic 
islands, a much larger proportion of the fauna is endemic, or 
consists of peculiar species and often of peculiar genera ; as is 
well shown by the case of the Galapagos and Juan Fernandez, 
both much nearer to a continent and both containing peculiar 
genera and species of birds. Now we know that the cause and 
meaning of this difference is, that in the one case the original 
immigration is very remote and has never or very rarely been 
repeated, so that under the unchecked influence of new condi- 
tions of life the species have become modified ; in the other 
case, either the original immigration has been recent, or if remote 
has been so frequently repeated that the new comers have kept 
up the purity of the stock, and have not allowed time for the 
new conditions to produce the effect we are sure they would in 
time produce if not counteracted. For Mr. Godman tells us 
that many of the birds are modified — instancing the gold-crested 
wren, blackcap, and rock dove — and he adds, that the modifica- 
