8 REVIEWS. 



natural affinities. The number of orders is so large that 

 practical convenience seems to require their arrangement into 

 groups subordinate to the primary classes ; and when man- 

 ifestly natural assemblages cannot be recognized, we are 

 obliged to employ those which, being less strongly marked, 

 and distinguished by a smaller number of characters, are 

 apparently of a more artificial nature. The arrangement em- 

 ployed by the learned Jussieu, in his celebrated " Genera 

 Plautarum," although to a considerable extent artificial, has 

 been almost universally adopted, until within the last few 

 years. 



In this method Dicotyledonous plants are primarily divided 

 into three groups : the first including those with a polyjje- 

 talous corolla ; the second, those with a monopetalous corolla ; 

 and the third, those destitute of a corolla. These sections are 

 subdivided (as also the Monocotyledons) by means of char- 

 acters taken from the insertion of the stamens (or corolla), 

 whether hypogynous, perigynous, or epigynous. The arrange- 

 ment here pursued, which is too well known to require further 

 notice, is substantially adopted by De Candolle, the difference 

 being more in appearance than in reality. Dr. Lindley dis- 

 carded these subdivisions in the first edition of his work ; but 

 the new distribution of the orders therein proposed possesses 

 few advantages, and indeed seems not to have satisfied the 

 author himself. In the same year with the publication of the 

 work just mentioned, the " Ordines Plantarum " of Bartling 

 appeared, in which a more natural arrangement of the orders 

 is attempted by the formation of aggregate or compound or- 

 ders, as originally proposed, and in several instances success- 

 fully accomplished, by Robert Brown. An analogous plan 

 was pursued by Agardh in his " Aphorismi Botanici " (1817), 

 and again in his " Classes Plantarum " (1825) ; but these at- 

 tempts, however ingenious, do not seem to have obviated, in 

 any considerable degree, the inconveniences of lineal arrange- 

 ment. 



We now return to our author, whose views upon this sub- 

 ject have been materially modified since the original publica- 

 tion of his Introduction of the Natural System. The method 



