106 OKGANOGIIAPHY. BOOK I. 



liad not received much attention ; the terms just mentioned 

 had been contrived to express certain of the most striking 

 forms of venation; but the application of these was far from 

 being sufficiently precise. Many improvements have been pro- 

 posed by modern botanists ; it however appears to me that the 

 whole nomenclature of venation is essentially defective, and 

 requires complete revision. My ideas upon this subject have 

 been already laid before the public in the Botanical Register 

 for Sept. 1826, page 1004.; and, as I am not aware that any 

 objection to them has yet been taken, I shall repeat them here, 

 in a form better adapted to an elementary work than that 

 under which they first appeared. 



The objections that I take to the present modes of distin- 

 guishing veins are these : — 1st, That the veins are very im- 

 properly, as I think, called nerves, either in all cases, as by 

 Link, which is bad, or in certain cases only, when they have 

 a particular size or direction, as by Linnaeus and his followers, 

 which is w^orse. Nothing is more destructive of accurate 

 ideas in natural history than giving names well understood in 

 one kingdom of nature to oigans in another kingdom of an 

 entirely different kind, unless it is tlie, perhaps, more repre- 

 hensible practice of giving two names conveying totally differ- 

 ent ideas to the same organ in the same kingdom of nature. 

 Thus, when the veins of a plant are termed nerves, it is neces- 

 sarily understood that they exercise functions of a similar 

 nature to those of the nerves of animals : if otherwise, why are 

 they so called ? But they exercise no such flinctions, being, 

 beyond all doubt, mere channels for the transmission of fluid. 

 Again, if one portion of the skeleton of a leaf is called a vein, 

 and another portion a nerve, this apparently precise mode of 

 speaking leads yet more strongly to the belief, that the struc- 

 ture and function of those two parts are as widely different as 

 the structure and function of a vein and a nerve in the animal 

 economy ; else why should such nice caution be taken to dis- 

 tinguish them ? But it must be confessed that there is no 

 difference whatever, except in size, between the veins and 

 nerves of a leaf. Let us, then, abandon a term which is one of 

 those relics of a barbarous age which it is the duty of modern 

 science to expel. 



My second objection applies to the vague manner in which 



