XVI INTRODUCTORY REMARKS. 



anticipate that there would be a marvellous similarity in the actual 

 faunas of the two Groups particularly when we recollect that their 

 physical conditions are nearly alike, and that the distance which 

 separates them is but trifling. And, accordingly, it will be found 

 that the genera are, on the whole, pretty much the same in both 

 archipelagos ; for although the more extensive list furnished by the 

 Canaries naturally includes within it many well-known forms (such 

 as Nebria, Carabus, Silplia, Hispa, Zophosis, Tentyria, Pimelia, Cossy- 

 phus, and Ocypus) which are absent from Madeira, the types which are 

 most esoteric, or peculiar, do decidedly permeate the entire archipe- 

 lago giving it a unity of character which it is impossible to mistake. 

 And yet, in spite of this, if we descend lower in the scale, and look 

 to the absolute species, it is surprising to find that their coincidence 

 falls far short of what we should have been led to expect from the 

 above considerations ; for whilst (as already stated) the number which 

 has been observed in the Madeiras is 661, and in the Canaries 1007, 

 only 238 have yet been detected which are common to the Groups. 

 Moreover even of that number there are exactly 38 which we may 

 properly deduct, as being (like the Carpopliili, Silvani, SitopTiili, 

 AlpTiitolii, Gnathoceri and Tribolium) unmistaTceable importations 

 through the medium of commerce, and which therefore have no real 

 connexion with the Atlantic fauna ; in which case there will remain 

 but 200 belonging equally to the Madeiras and Canaries. How we 

 are to interpret this remarkable fact I will not now stop to conjec- 

 ture ; but I may perhaps have occasion, further on, to allude to it 

 again*. 



Local Statistics. In investigating the natural history of an oceanic 

 Group, it should be borne in mind that we have a far more intricate 

 task to achieve than if our field of research had been a continuous 

 land. In the latter case, it is but a single (though more or less pro- 



* After discarding the 38 species above referred to, which have without doubt 

 been introduced through human instrumentality (as indeed is the case with them 

 in almost every country of the civilized world), it is marvellous to note how few 

 there are even of the remaining 200 which I should regard as positively endemic. 

 In fact no less than 66 of these, there can be little question, must have been natu- 

 ralized within a comparatively recent period ; and even the 134 to which we 

 are thus ultimately reduced contains but a small proportion which are purely 

 " Atlantic," the majority of them being found equally in Mediterranean 

 countries. So that the actual species which range over the entire archipelago 

 would appear to be not only few in number (compared with the extent of the 

 Madeiran and Canarian faunas), but also on the whole commonplace, and that, 

 too, whilst the most peculiar and characteristic genera in the two Groups are 

 absolutely identical. 



