250 NOTICES OF BOOKS. 



in elevation or latitude or longitude, by climate, or soil, or other ex- 

 ternal conditions. Species, Genera, and Orders stop, we see not why, 

 and often reappear where we least expect them. Under this head 

 too must be noticed the fact that there is none of that recognizable 

 relation between structure and function, or structure and external 

 conditions, in the vegetable kingdom that there is in the animal, and 

 which often enables us to account for a fact in the distribution of an 

 animal by another in that of a plant. We see the limit of some ani- 

 mal's distribution coinciding with that of the plant it lives upon or 

 under, or that nourishes a third animal it preys upon ; but we never 

 see the plant stopped by or for the animal. There are comparatively 

 few evidences of plants being structurally better suited to one situa- 

 tion than to another, with the exception of a few conspicuous classes, 

 as water-plants, epiphytes, parasites, etc.j and hence our power of ac- 

 counting by physical causes for the facts of Botanical Geography is 

 extremely limited. 



If, again, we turn from those branches of the subject, in reasoning 

 upon which we make use of facts and observations however inexact or 

 difficult of application, to the fundamental principles upon which the 

 study is based, and from some of which we must start in all our inves- 

 tigations, we enter at once into the regions of pure speculation. Nor 





can there be better proof of the facts and hypotheses advanced bein 

 insufficient to explain Geographical distribution, than is afforded by 

 the cii'cumstance that even M. de CandoUe, with all his philosophy 

 and desire to arrive at exact conclusions, is compelled to resort to the 

 unphilosophical proceeding of demanding the operation of two laws to 

 account for each of the two primary phenomena connected with the 

 creation of species. 



Thus, with regard to their origin, he considers that most are special 

 creations, but that some are the offsprings of transmutations ; and with 

 regard to the number created and place of creation, that some are 

 created as solitary individuals or as a plurality of individuals in one 

 place only; and that others are (simultaneously?) created in several 

 more or less distant localities. 



We arc told that the majority of species were created such as they 

 now exist, but there is not a shadow of a proof of this. No amount 

 of acute observation or critical disquisition throws real light upon 

 this subject, upon which men of science are completely at issue ; nor 

 IS there in the present state of science any prospect of naturalists 



