CLASSIFICATION OF PLANTS. (BY THE EDITOE.) 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 Polypetalous Orders, 

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

 in either Monopetalse or Polypetalae ; 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 Polypetalse and Monopetalse, guided by affinity, when that is known, and by 

 analogy in other cases. To me 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 Monopetalee; and secondly, because it contains so many which, though 

 closely allied to others amongst Polypetalse, 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 

 H^ypogynous, 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 Baniinculacece to perigynous Legu- 

 minosos, and from these again to epigynous Araliaoeoe, which indisputably establish a direct 

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

 Thalamifloral and Calycifloral series, lies in the fact that (putting aside the many casgs 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 Anaeardiece, 

 Gonnaracece, Burseracece, and Oelastrineoe, all of which are regarded as perigynous by De 

 OandoUe ; and as perigynous Caryophyllece, Elatmece, and Olacineoe, which De Candolle 

 and Lindley rega,rd 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 Disciflorte. 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 Monopetalse exhibit 

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

 that they should, in preference to Polypetalse, head a system founded on this consideration.' 



But if Monopetalse be chosen to head the Dicotyledons, Gompositce should lead ofi^, 

 followed by Valerianeoe, Buhiacece, and Gaprifoliaoece, Orders that establish the passage to 

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

 OornecB and the other Polypetalse, would be followed by the Campanal Cohort, a group 

 more closely allied to Gompositce than are Ruhiacece, &c. This suggests the expediency 

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

 Dicotyledons, beginning with Valerianece, Buhiacece, and GaprifoUacecs, which lead to the 



' Separation of the sexes, which in the Animal King- in plants the transmission of the sperm-cell 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 individijal of _either sexj 

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



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