TAXONOMY AND PHYTOGEAPHY. 



HI 



many cases is even of no further use, than in discrimi- 

 nating certain varieties of the same species. 



5. The relative periods at which different organs 

 are formed and developed, may also be taken as some 

 test of their relative importance ; those which are the 

 earliest formed, being considered more important than 

 others with which they are immediately connected, and 

 of the same class. 



By attention to these and a few other rules of less 

 general application, a subordination of characters has 

 been established, of which the chief results are exhibited 

 in the following table : 



Relative 

 Values. 



Elementary. 



Cellular Tissue 

 Vascular Tissue 

 (a) Tracheae 

 (6) Ducts 

 Stomata 



Nutritive. 



Reproductive. 



5. 



Embryo and 'j 

 Sporule 



(a) Cotyledons > 

 (6) Radicle 

 (c) Plumule J 



"(1) Stamens and 



Pistils. 



(2) Fruit, Peri- 

 [^ carp, Theca. 



{Perianth. 

 (a) Corolla. 

 (6) Calyx. 

 |" Inflorescence, 

 J Torus, Nectary, 

 "J Bractea, Invo- 

 (_ lucre. 



Root, Stem, 

 Leaf, Frond, 

 Thallus 



(134.) Relative Importance of similar Organs. Be- 

 sides the relative values of different organs, established 

 in this table, we may estimate the relative value which 

 two organs of the same kind bear to each other, in dif- 

 ferent species. This will depend upon the greater or less 

 perfection which they exhibit in their respective modes 

 of development ; also, upon their position, connection 

 with other organs, and numerous other particulars which 

 it is impossible to define with any degree of precision, 



