XIV • PBOCEEDINGS OF THE 



Three diiFerent hypotheses are now more or less imder discussion. 



1. That the individuals now Hving have descended from as many- 

 common stocks as there are distinguishable varieties or geographical 

 races or areas of dispersion, these common stocks being the result of 

 special creations, either simultaneous or consecutive. 



2. That the whole of the individuals belonging to each species 

 (including often several more or less permanent races) are descended 

 from one specially created common stock, from which they have 

 gradually spread to the different parts of the world they now in- 

 habit. 



3. That the races now occupying the globe are lineally descended 

 from those ancient and very different races which preceded them, by 

 a gradual process of variation and extinction, according to pre- 

 established laws still more or less actively in operation. 



The first hypothesis, that of several centres of creation or origin 

 for each species, was a favourite one among several Continental 

 naturalists, especially botanists, a quarter or half a century since. 

 It is, I believe, still maintained, either directly or disguised tmder 

 the form of admitting distance of geographical area as a specific 

 distinction, by Agassiz, by Carl Miiller and others in Germany, as 

 well as by some French botanists of the school of Lecoq, whose volu- 

 minous writings on geographical botany I do not find in any of our 

 libraries, and am therefore unable to refer to. My recollection of 

 them is, however, that the speculations they contain are founded chiefly 

 on the geology and botany of a very Kmited district, and therefore 

 of little weight with the general naturalist. And when LyeU, Forbes, 

 and others broke down the Kmits previously assigned to the possi- 

 bility of dispersion by the prevalent ideas of impassable geographical 

 obstacles, the theory of separate creations became no longer neces- 

 sary to account for observed phenomena : it was tacitly given up by 

 many, and openly renounced by A. DeCandolle in his * Geographic 

 Botanique.' It has, however, been recently revived by some ethno- 

 logists, and especially by the President of the Ethnological Society, 

 Mr, J, Crawfurd, in a series of papers read before that Society. His 

 arguments however relate exclusively to Man, and they are there- 

 fore based not so much on difficulties of dispersion as upon the sup- 

 posed immutability of races when not modified by hybridism, on the 

 presumed distinctness of type in languages, and other questions of 

 fact upon which ethnologists are by no means unanimous. 



The second hypothesis, that of the independent creation of one 

 common stock for each species now existing on the globe, has been 

 at all times the one most generally received, acknowledged, and taught 



