THE CHIEF COLEOPTEROUS FAUNAE. 



67 



law to which I have already referred as regulating the introduction 

 of new species to new countries, viz. that if it be full, they make 

 little way — if empty, rapid progress. 



I make these flying shots at a covey of dates ; not that I ima- 

 gine that difficult problems like these are to be unloosed by crude 

 generalizations from the few uncertain facts of doubtful import 

 which we possess, but as illustrations of the kind of use to which 

 some of the principles which I see only dimly looming through 

 the haze, but which I do believe to have truth and substance in 

 them, may be put when we have got more facts and know better 

 how to use them. One fact seems to shine clear out of the mist ; 

 and that is that in all those countries where different types have 

 made good their footing, the races seem to preserve their identity 

 for all time, mixed but never blending, approximated but never 

 amalgamated. If hybridism be an agent at all in the production 

 of new species, it certainly carefully confines itself to its own type. 



The islands in the Indian Ocean between India and Africa 

 (Mauritius, Reunion, &c), exclusive of Madagascar and its im- 

 mediate dependencies, are partly Indian, partly African and Ma- 

 lagasse. Madagascar is a land of wonders, not only for what it 

 contains, but for its relations with other countries. The basis of 

 its fauna is African ; but it has also elements of its own, some of 

 which may be traced far off, and in countries which have lent it 

 something in return. We do not yet know how these peculiari- 

 ties are distributed in the island. One collector goes to Mada- 

 gascar, and he finds little or nothing but common African forms. 

 Another goes to some other part of the island (some of them, es- 

 pecially the older ones, have not been so particular as we now find 

 it necessary to be in reporting the localities searched and their 

 products), and he sends home the most wonderfully attractive and 

 strange forms it is possible to conceive. A double fauna is cer- 

 tainly represented there — one African and the other American — 

 some have said allied to North America, others to Mexico, and 

 others to Brazil. It is a slight tincture of the Brazilian stirps 

 which is found in all three. The African connexion will, I dare 

 say, be admitted. The Brazilian is proved by the presence 

 in Madagascar of various representatives of Brazilian forms. 

 Thus Polybothris represents the Brazilian Psiloptera ; Doryscelis 

 represents Gymnetis ; Stig motmchelus, Platyomus ; JPeltis Ivanii 

 is found in both ; but by far the most convincing instance is a 

 moth of the genus Urania (to my mind, the most gorgeous Lepi- 



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