358 ANNUAL OF SCIENTIFIC DISCOVERY. 



are, at least as to species, and to a considerable amount as to genera, 

 different from those of other zoological and botanical regions. They 

 are respectively adapted to certain conditions of existence, such as 

 climate, temperature, mutual relations, and, no doubt, other circum- 

 stances of favorable influence which men have not yet discovered, and 

 which may never be discovered in the present state. These conditions 

 cannot be transferred to other situations. The habitation proper to 

 one description of vegetable or animal families would be intolerable, 

 and speedily fatal, to others. Even when, as in many parts of the two 

 hemispheres and on the contrary side of the equator, there is appa- 

 rently a similarity of climate, we find not an identity, but only an 

 analogy of animal and vegetable species. These opinions have met 

 with violent opposition from some prejudiced minds ; but the more 

 these views are examined, the more self-evident they become : whence 

 Sir Charles Lyell's observation, that naturalists have been led " to 

 adopt very generally the doctrine of specific centres ; or, in other 

 words, to believe that each species, whether of plant or animal, origi- 

 nated in a single birth-place." M. De Candolle has suggested twenty- 

 seven of these independent regions for plants, and the Rev. J. S. 

 Henslow forty-five. For the inferior animals D. Prichard proposes 

 seven regions, Mr. Swainson five, Prof. Hitchcock eleven, Mr. Water- 

 house also eleven, but with some geographical differences ; and Sir 

 Charles Lyell, Prof. Agassiz, and many, if not all, the continental 

 zoologists of the present day, are united in sentiment on this principle. 

 How unjust, therefore, it is to attempt to brand as infidels those who 

 adopt an opinion irresistibly derived from an examination of the truths 

 of nature, and which has the sanction and support of such names as 

 we have enumerated ! It is necessary, however, to add, that most of 

 these authorities make the human species an exception, and the sole 

 exception, to this doctrine of independent creations. 



EXPLANATION OF THE RAPID DECREASE OF THE NATIVE POPULATION OF 



POLYNESIA. 



THE fertility of hybrid races, originating in the intermixture of two 

 races whose affinity is most remote, is a fact of which there can be no 

 doubt whatever ; and there is strong reason to believe that these 

 hybrid races, the parents of which are Europeans on one side, and the 

 aborigines of any country on the other, are generally destined to 

 become the dominant population of those countries. For, on the one 

 hand, these " half castes " very commonly combine the best attributes 

 of the two races from whose admixture they spring, namely, the 

 intelligence and mental activity of the European, and the climatic 

 adaptation of the native ; and they are also in general distinguished 

 for their fertility, when paired with each other, so that they are rap- 

 idly rising into numerical importance. On the other hand, this very 

 intermixture, taking place, as it usually docs, between a European 

 father and a native mother, tends to diminish the number of the native 

 population in a very remarkable manner ; for there is now a large 

 amount of evidence, that Avhen a native female of the Americans or 

 Polynesians has once been impregnated by a European male, she 



