990 



its green herbaceous petals, to the latter ; notwithstanding the conspi- 

 cuous coloured petals of the exotic genus, Trillium, belonging to the 

 same order. And this leads to some remarks upon the author's notions 

 of a natural system as set forth in this volume. 



Entertaining the idea " that the principles of vegetable transforma- 

 tion or morphology might be made available in the formation of the 

 higher divisions of flowering plants," he thus proceeds to explain his 

 views as to the applicability of this doctrine to the arrangement of 

 plants in a natural manner. 



" To effect these metamorphoses, it is apparent that some special 

 vital forces are called into action; and we are justified in the infe- 

 rence, that those flowers which exhibit the most extensive departures 

 from the original tyj)e, as the result of a more intense action of those 

 forces, ought to be regarded as possessing a higher structural nature 

 than those wherein the primitive model may be more evidently traced. 

 It is manifest then, that the most simple metamorphosis the leaves 

 undergo is in the production of flowers, all the parts of which most 

 nearly resemble the former in being distinct from one another ; and 

 that when these separate parts appear in a new condition, by their 

 cohering more or less intimately with each other, a more complete 

 alteration is effected. Therefore it is, I conceive, that flowers whose 

 parts thus cohere, are to be considei'ed as possessing a more exalted 

 structure than those in which the several floral whorls and the mem- 

 bers of each are distinct. 



" In the construction of a system for the arrangement of flowering 

 plants according to these views, the following principle may be 

 enunciated : — That plants whose Jlowers exhibit their several parts in 

 a state of separation, are to be placed in a loiver position than those 

 in ivhich their several parts are in a state of cohesion ; and on this 

 principle, the table of natural orders immediately preceding the 

 descriptions is constructed." — p. vi. 



In carrying out these views the author first divides the Exogens into 

 three groups — Diclinous, Hypogynous and Perigynous; thus appa- 

 rently suppressing the epigynous orders, though in reality merging 

 the perigyns of other botanists in the hypogynous orders, and giving 

 the name of perigynous to the epigyns proper. To this arrangement 

 we cannot subscribe. We are of opinion that no mode of division can 

 be more natural than that applied to the Exogens by Lindley in his 

 ' Vegetable Kingdom,' where they are primarily broken up into two 

 groups, the one diclinous, in which the flowers are absolutely unisex- 

 ual ; and the other hermaphrodite, or possessing both stamens and 



