﻿ON THE BOTANY OF JAPAN. 445 



that De Cantlolle would now explain these cases in accordance with the general views 

 of distribution adopted by him, under which they naturally fall, — so abandoning the 

 notion of a separate creation. 



I know not whether any botanist continues to maintain Schouw's hypothesis. But 

 its elements have been developed into a different and more comprehensive doctrine, 

 that of Agassiz, which should now be contemplated. It may be denominated the 

 autochthonal hypothesis. 



In place of the ordinary conception, that each species originated in a local area, 

 whence it has been diffused, according to circumstances, over more or less broad tracts, — 

 in some cases becoming widely discontinuous in area through climatic or other physical 

 changes operating during a long period of time, — Professor Agassiz maintains, sub- 

 stantially, that each species originated where it now occurs, probably in as great a 

 number of individuals occupying as large an area, and generally the same area, or 

 the same discontinuous areas, as at the present time. 



This hypothesis is more difficult to test, because more ideal than any other. It 

 might suffice for the present purpose to remark, that, in referring the actual distri- 

 bution, no less than the origin, of existing species simply to the Divine will, it would 

 remove the whole question out of the field of inductive science. Regarded as a philo- 

 sophical question, Maupertuis's well-known " principle of least action " might be legiti- 

 mately urged against it ; namely, " that it is inconsistent with our idea of Divine wisdom, 

 that the Creator should use more power than was necessary to accomplish a given end." 

 This philosophical prmciple holds so strictly true in all the mechanical adaptations of 

 the universe, as Professor Peirce has shown, that we cannot think it inapplicable 

 to the organic world also, and especially to the creation of beings endowed with such 

 enormous multiplying power, and such means and facilities for dissemination, as most 

 plants and animals. Why then should Ave suppose the Creator to do that supernat- 

 urally which would be naturally effected by the very instrumentalities which he has set 

 in operation ? 



Viewed, however, simply in its scientific applications to the question under consid- 

 eration, (the distribution of plants in the temperate zone of the northern hemisphere,) 

 the avitochthonal hypothesis might be tested by inquiring whether the primitive or 

 earliest range of our species could possibly have remained unaffected by the serious and 

 prolonged climatic vicissitudes to which they must needs have been subject; and 

 whether these vicissitudes, and their natural consequences, may not suffice to explain 

 the partial intermingling of the floras of North America and Northern Asia, upon 

 the supposition of the local origin of each species. Let us bring to the inquiry 



VOL. VI. NEW SERIES. 67 



