236 Bibliographical Notice. 
repay perusal. Nevertheless it does appear to us that we have here 
an example of gradually increasing segregation, probably extending 
over a very long period of time, with change of external conditions, 
resulting, at all events in some cases (if Mr. Wollaston’s notion of 
these derivative species be correct), in the production of forms differ- 
ing by slight characters from the original type. The Darwinist will 
say that the other forms, the specific rank of which, according to 
Mr. Wollaston, is not doubtful, have probably required and under- 
gone a greater amount of modification to fit them for their altered 
conditions of existence. Under any circumstances, it seems to us 
that the insect fauna of the Atlantic islands furnishes naturally 
almost an experimental realization of the conditions necessary for the 
origin of species by evolution from preexisting types; and a good 
naturalist, without theoretical bias (if such a being can be found), 
might certainly do much towards the settlement of this questio vexata 
by a careful investigation of the ‘Coleoptera Atlantidum,’ under Mr. 
Wollaston’s guidance. In connexion with this, the curious facts 
presented by the study of the dominant forms of Beetles in these 
islands (adverted to by the author in Col. Atlant. xxii-xxv) will be 
of particular importance. 
This notice has already extended to such a length, that several 
points to which we might otherwise have referred must be passed in 
silence. We may, however, state in general terms that the whole in- 
troduction to the ‘Coleoptera Atlantidum,’ extending to 47 pages, 
is replete with interesting observations and remarks, and gives an in- 
creased significance to the systematic portion of the work. Both the 
‘Catalogue of Canarian Coleoptera’ and the ‘Coleoptera Atlantidum ’ 
contain descriptions of a great number of species: in the former 
work these are introduced in their places in the Catalogue; in the 
latter they are given in an Appendix, and only referred to in the body 
of the work. Both contain excellent topographical indexes,—that in 
the ‘ Catalogue’ showing the species inhabiting the various islands of 
the Canarian group, whilst that appended to the ‘Coleoptera At- 
lantidum’ exhibits only the faunal relations of the three groups of 
islands. The latter work is illustrated with an outline map. 
Thus in the two volumes now before us, and in his ‘ Insecta Made- 
rensia,/ Mr. Wollaston has fulfilled one of the highest tasks of the 
zoologist: he has worked out, in an almost exhaustive manner, the 
members of an extensive group of animals inhabiting a well-defined 
area ; and having aimed at perfection in his work, it must be confessed 
that he has perhaps attained it as nearly as is possible to man. We 
can only hope that his present visit to the more southern islands of 
the Atlantic may lead to equally valuable results—a hope in which 
all entomologists will certainly agree with us. 
