CLASSIFICATION OF PLANTS. (BY THE EDITOR.) 993 



great group of Angiospermous Dicotyledons, the Incomplete-flowered or Diclinous. These 

 consist in great part of Orders which are manifestly very near allies of Polype talous Orders, 

 and in part of Orders or groups of Orders that have no recognized close affinity with any 

 in either Monopetalae or Polypetalse ; and the fact of the presence or absence of floral 

 envelopes being no positive proof of affinity, has led to the abandonment of the Incomplete- 

 flowered division by Brongniart and other systematists, and the dispersion of its members 

 amongst the Polypetalae and Monopetalae, guided by affinity, when that is known, and by 

 analogy in other cases. To ine it appears that, under a classificatory point of view, the 

 adoption of an Incomplete division cannot be avoided : firstly, because it contains so many 

 natural and well-established cohorts that have no recognized affinity with any amongst 

 either Polypetalae or Monopetalae; and secondly, because it contains so many which, though 

 closely allied to others amongst Polypetalee, could not be intercalated amongst these with- 

 out disturbing their sequence, thus sundering Orders that should stand in contiguity. 



The subdivision of the Polypetalous Dicotyledons by Jussieu and De Candolle into 

 Hypogynous, Perigynous, and Epigynous, has been by many authors objected to as arti- 

 ficial ; but I think it cannot be doubted that the characters indicated by these terms are 

 guides to affinity, and that, exceptions notwithstanding, there is a recognizable, though 

 often distorted, sequence of Orders from hypogynous Ranuncitlacece to perigynous Legu- 

 minosce, and from these again to epigynous Araliacece, which indisputably establish a direct 

 passage to the epigynous Monopetalae. The great obstacle to the recognition of the 

 Thalamifloral and Calycifloral series, lies in the fact that (putting aside the many cases of 

 hypogynous Orders containing perigynous genera) there are many Orders of which it is 

 difficult to say to which they belong. Thus Brongniart regards as hypogynous Anacardiece, 

 Connaracvce, Burseracea?, and Celastrinece, all of which are regarded as perigynous by De 

 Candolle ; and as perigynous Garyopliyllece, Elatinece, and Olacinece, which De Candolle 

 and Lindley regard as hypogynous. To reduce this difficulty, Mr. Bentham and I, ob- 

 serving that a highly developed staminiferous disk prevailed in the Orders that intervened 

 between the manifestly perigynous and hypogynous Orders, collected them into a division of 

 Polypetalae, called Series Disciflorae. In doing this, we did not look on the disk as a proof 

 of affinity, but as a guide to that amount of affinity which certainly exists between 

 the Orders included under that Series. 



It remains to say a few words on the sequence of Dicotyledonous Orders here adopted. 

 That a linear, and at the same time natural sequence is unattainable, is conceded by all 

 philosophical systematists. It is further, I think, established that the Monopetalae exhibit 

 the greatest departure from the imaginary primitive type of the Dicotyledonous flower, and 

 that they should, in preference to Polypetalaa, head a system founded on this consideration. 1 



But if Monopetalae be chosen to head the Dicotyledons, Composites should lead off, 

 followed by Valerianece, Rubiacece, and Caprifoliacece, Orders that establish the passage to 

 epigynous Polypetalae : under which arrangement, Caprifoliacece, &c., instead of leading to 

 Cornece and the other Polypetalae, would be followed by the Campanal Cohort, a group 

 more closely allied to Composite than are Rubiacece, &c. This suggests the expediency 

 of following De Candolle in placing the epigynous Monopetalae in the middle of the 

 Dicotyledons, beginning with Valerianece, Rubiacece, and Caprifoliacece, which lead to the 



1 Separation of the sexes, which in the Animal King- in plants the transmission of the sperm-eell or 



dom is universal amongst the higher groups, is in the antherozoid to the pistil or germ-cell is directly 



Vegetable Kingdom no indication of a high or low brought about by external agencies, and not by the 



development ; and is a fallacious guide to affinity. spontaneous action of the individual of either sex. 

 This is, no doubt, connected with the fact, that 



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