346 REVIEWS. 



Then in the Corolliflorse we have a synpetalous corolla to which the 

 androecium entirely adheres, whilst the calyx exteriorly, and thegynoe- 

 cium within, remain distinct. This is not unnaturally regarded as a 

 special form of structure, yet if we' make the adherence of the androe- 

 cium outwardly without attachment to the ovary the main point, this 

 will he, as Lindley makes it, only a variety of Perigynose structure. 

 De Candolle's Monochlamydese is a very miscellaneous group, for the 

 separation of which a new principle is introduced and one which forms 

 very harsh, and unnatural combinations. It is plain from his own 

 words that this great botanist only considered his subdivision of Exo- 

 gens as a temporary expedient to which he attached no importance, 

 and in fact the prevalence of his method is to be attributed much more 

 to its being the method of his invaluable Prodromus than to its own 

 intrinsic merit. 



Dr. Gray, whilst following pretty exactly De Candolle's series, 

 neglects his sectional divisions, substituting a very simple triple 

 division of Exogens into Polypetalous (much better called Ap- 

 opetalous) in which division are included those plants in which, 

 whilst all the exterior circles adhere over the ovary, the parts of the 

 corolla above the inferior fruit are separate ; Monopetalous (rather 

 say synpetalous) where the petals cohere into a tubular corolla ; and 

 Apetalous in which the corolla is entirely absent. Under each of these 

 divisions the orders are collected into groups intended to be more or 

 less natural and thus imitating Lindley' s alliances. This latter ar- 

 rangement is a decided improvement, and the former may be consi- 

 dered as affording practical facility to the working botanist without 

 the sacrifice of any principle. There are, indeed, numerous excep- 

 tions, but the student soon learns to be on his guard against them, 

 and does not find them a source of serious diSieulty. 



The method of Dr. Lindley is explained and applied in his valuable 

 work, "The Vegetable Kingdom." His division of Exogens, excluding 

 from them the Gymnogens or Gymnosperms, is founded first on the com- 

 pleteness of the flower as to its reproductive system, or its diclinous char- 

 acter, which consists in the suppression in each flower of one of the 

 reproductive circles of parts. The former group is subdivided according 

 as the flower is hypogynous, perigynous, or epigynous in the insertion 

 of its organs. Thus we have four sub-classes or great sections of 

 Exogens as in De Candolle's method : but according to Dr. Lindley's 

 view, the divisions are somewhat more natural and considerably easier 



