4 REVIEWS. 



explanations to show the fallacy of the common opmion that 

 the artificial system of Linnaeus is easy, and the Natural Sys- 

 tem difficult of application. The sentiments of the public 

 have undergone so great a change upon this subject within 

 the last five or six years that he finds it no longer necessary to 

 adduce these considerations, and accordingly commences at 

 once with a development of the principles on which the Natu- 

 ral System is founded, namely, ''That the affinities of plants 

 may be determined by a consideration of all the points of 

 resemblance between their various parts, proj)erties, and 

 qualities; that thence an arrangement may be deduced in 

 which those species will be placed next each other which have 

 the greatest degree of relationship; and that consequently 

 the quality or structure of an imperfectly known plant may 

 be determined by those of another which is well known. 

 Hence arises its superiority over arbitrary or artificial systems, 

 such as that of Linnaeus, in which there is no combination of 

 ideas, but which are mere collections of isolated facts, not hav- 

 ing any distinct relation to each other." (^Preface, p. vii.) 



We have never met with a more clear and succinct account 

 of the principles upon which the primary divisions of the 

 vegetable kingdom rest than that comprised in the follow- 

 ing extract. Those acquainted with the first edition will per- 

 ceive that the author has changed his opinions respecting the 

 number of these primary divisions or classes; the Gymno- 

 spermce^ or Flowering plants with naked ovules (comprising 

 the Coniferce^ Cycadece^ and, according to Brongniart and 

 Lindley, the Eqidsetacece)^ and the RMzantJim^ as ori- 

 ginally established by Blume, being here admitted to the 

 rank of independent classes. Their claim to this rank, how- 

 ever, can as yet be hardly considered as fully established. 



" One of the first things that strikes an inquirer into the 

 structure of plants is the singular fact that while all species 

 are capable of propagating their race, the mode in which 

 this important function is accomplished is essentially different 

 in different cases. The great mass of plants produce flowers 

 which are succeeded by fruits, containing seed, which is shed 

 or scattered abroad, and grows into new individuals. But in 



