20 



some of their original fauna, which would be of Asiatic character ; and on the 

 other hand the eastern islands, beginning with Lomboo and the Celebes, have 

 probably had some connexion with New Guinea or Australia, though in all 

 probability tlieii- relationship to each other is immensely more remote than that 

 between the isles of Sumatra, Java, and Malay. 



These facts, viz., the dissimilarity of the faunas of widely-separated countries, 

 though perhaps of the same climate and conditions, the peculiarity of island 

 faunas, and yet their evident relationship to the nearest mainland, or at any 

 rate to the mainland with which they were originally connected ; and the fact 

 that those most isolated in space or time, have the most differentiated or pecidiar 

 faunas, — These facts, I say, seem to me to point clearly to centres of creation, 

 with subsequent migration and concomitant modification. 



It is, of course, impossible to say where the original centres of creation were, 

 and how many of them there may have been. The theory of Mr. Darwin would 

 limit the number almost to a single pair. Without going as far as that, I cannot 

 help thinking that the number of centres was less numerous by far than the existing 

 number of species ; possibly they might bear some relation to the great families, 

 such as the Felidre, tlie Equidre, and the Cervidas ; but this is an idea which at 

 present I am not able to elucidate. 



The great difficulties to be overcome in accepting the view of a limited 

 number of centres of creation are the difficulty of migration, and the difficulty of 

 modification to the extent necessary. 



With regard to the latter of these difficulties, I think the example of the 

 domestic animals, the vai'ieties of which are almost certainly known to have 

 proceeded from a single species is sufficient to prove that an immense amount of 

 variation is capable of being produced in some animals, at least, by altered 

 circiunstances and careful selection, at any rate as far as regards such characters 

 as size, colour, prolificacy, and many others more or less of a superficial nature. 



Granting this, which can hardly be denied, that in most animals there is a 

 certain amount of inherent variation which can be brought out by altered 

 conditions of life, there is no insuperable difficulty in believing that the species 

 of some natural family may have all proceeded from some common progenitor ; 

 further than that it is not prudent, I think, to go. 



The other difficulty that of migration will be a legitimate topic to say a few 

 words upon in this paper. 



If we concede what I for one am inclined to do, that the centres of creative 

 action were less numerous than the existing species now on the face of the earth, 

 it will be necessary to show how migi-ation to all the inhabited pai'ts of the 

 world may have been effected. 



With regard to the diffusion of the lowest classes of Ufe, namely, those sub- 

 kingdoms Coslenterata or Polyps, and Protozoa which contains the Sponges and 

 Infusorial Animalcules and the Foraminifera, it easy to understand how their 

 diffusion may have been effected. 



