Fhih'iopkkal Character of Decaadoile. 233 



he proceeds upon the principle of tracing each organ through 

 all its several modifications of structure in the different plants 

 in which it occurs, and of reducing every part to its organic 

 elements. Hence the whole of this treatise may be regarded 

 as in some sense a development of the great doctrine of me- 

 tamorphosis, which he had pointed out in his foregoing trea- 

 tise—a detailed exposition of the symmetrical plan, which the 

 parts of all plants affect, and of the causes which interfere 

 with their regularity of form and disposition. 



It is this philosophical mode of considering the structure 

 of plants, which has mainly contributed to impart to the work 

 of Decandolle the superiority which it possesses over all an- 

 tecedent, all contemporaneous treaties on botany, and which 

 has even rendered it in many respects a model for those which 

 have subsequently appeared. 



The organs of vegetables are here set before us, not in dry 

 detail, as separate and independent parts of the structure which 

 they serve to make up, or even in a purely physiological point 

 of view, as subservient to the uses of the individual of which 

 they are a constituent ; but they are treated, as links of a com- 

 mon chain, as portions of the same harmonious system, sub- 

 ject indeed to endless variations, and productive of continual 

 diversities of form and function, but nevertheless all influenced 

 by the same universal law of symmetry and order. 



One of the greatest advantages attendant on this mode of 

 treating the subject of botany, is the facility which it affords 

 us of conveying a clear conception of, and in imprinting upon 

 the memory, the numerous varieties of structure, which we 

 adopt in describing and distinguishing individual plants. 



How perplexing, for instance, is the enumeration of the dif- 

 ferent kinds of seed-vessel, according to old books on botany 

 founded on the Linnsean method of classification ! how weari- 

 some to the mind, to burden itself with the names and defini- 

 tions of a long string of objects, between which no relation or 

 connexion of form has been pointed out to us ! 



But, according to Decandolle's method, all these several 

 forms of organization are shewn to result from leaves variously 

 modified, and adherent ; and thus, whilst engaged in the in- 

 teresting task of reducing all these variations of form to one 

 common symmetrical plan, we are insensibly led to classify 



