150 OEIGINAL AETICLES. 



as of generic importance, many of the most natural groups in those or- 

 ders have been broken up, and split down almost to single species, classed 

 into purely artificial tribes and sub -tribes. So, also, a character gene- 

 rally important may, in some instances, separate a single species from a 

 large order with which it may agree in every other respect. The dis- 

 memberment of such exceptional species from that order, — as, for in- 

 stance, that olPhryma from Verbenacese, — becomes then purely artificial, 

 and contrary to all principles laid down for natural classification. 



This introduction of artificial arrangements, under the disguise of a 

 strict adherence to the rules of the natural system, is much promoted 

 by a tendency to which we systematists are all very liable. It has hap- 

 pened to most close observers to have on some occasion brought for- 

 ward some character till then comparatively neglected, but which has 

 proved to be eminently useful for establishing natural groups in par- 

 ticular genera, orders, or classes. Such a character is then apt to as- 

 sume an undue importance in the observer's mind, and to be applied by 

 him indiscriminately throughout the vegetable kingdom. The arrange- 

 ment of the parts of the floral whorls with relation to the main axis of 

 inflorescence, the aestivation of the floral envelopes, the relative attach- 

 ment of the floral whorls, and consequent modifications in form of the 

 torus, disk, or floral receptacle ; the numbers absolute and relative of the 

 parts in the several floral whorls, the position of the ovary with relation 

 to the rest of the flower, that of the ovules with relation to the ovary, 

 the structure of the fruit, and even the most important of all, the rela- 

 tion of the embryo to the seed, and, the seat of deposit of starch for sup- 

 plying the first nutriment to the growing embryo — whether as albumen 

 around it, or in its cotyledons, or in the intermediate point (the collet) 

 between the radicle and cotyledons — all characters which more or less 

 generally mark out large and highly natural orders, have nevertheless, 

 each in their turn, on some occasion or other, been applied too strictly, 

 so as to dissever groups otherwise most natural. 



On the other hand, however closely we follow natural indications, 

 our system must be to a certain degree artificial. A purely natural me- 

 thod of arranging species and genera is impossible ; at least, none has 

 ever been brought forward. The affinities and cross-affinities of plants 

 are so complicated and intertwined, that we have no method of repre- 

 senting them either by a linear series, or by mapping them out on a 

 plane surface. Many of the most natural groups have no definite limits ; 

 and yet, to form any clear idea of them for the purpose of study, we 

 must assign limits. The truly German idea of taking one species or ge- 

 nus as a normal type of a genus or order, and grouping others around it 

 as more perfect, or reduced, or collaterally aberrant forms, leads to no 

 practical results. However well it may read in chamber speculations, 

 it produces nothing but confusion when applied to the actual grouping 

 of species. There is no plant which arguments like those usually 

 brought forward may not show equally well to be an aberrant form of 

 almost any number of different types. The absurdity of such a system 

 appears to me never to have been so fully exemplified as in an elaborate 



