ITS VARIOUS MODIFICATIONS. 245 



branch, of which we have shown the flower to be a modified con- 

 tinuation, so that in the flower we are to expect no organs other 

 than those that, whatever their form and office, answer either to 

 the axis or to the leaves, or, in other words, to phytons (230) ; so 

 that the differences between one flower and another are to be ex- 

 plained as special deviations from, or circumstantial variations of, 

 one fundamental plan, variations for the most part similar or 

 analogous to those which are known to occur in the organs of veg- 

 etation themselves. Having assumed the type which represents 

 our conception of the most complete, and at the same time the 

 simplest flower, we apply it to all the cases which present them- 

 selves ; and especially to the elucidation of those blossoms in 

 which the structure and symmetry are masked or obscured ; where, 

 like the disenchanting spear of Ithuriel, its application at once re- 

 veals the real character of the most disguised and complicated 

 forms of structure. 



446. Our pattern flower consists of four circles, one of each 

 kind of floral organ, and of an equal number of parts, successively 

 alternating with one another. It is complete, having both calyx 

 and corolla, as well as stamens and pistils (416) ; symmetrical, 

 having an equal number of parts in each whorl (436) ; regular, in 

 having the different members of each circle all alike in size and 

 shape ; it has but one circle of the same kind of organs ; and 

 moreover all the parts are distinct or unconnected, so as to exhibit 

 their separate origin from the axis or receptacle of the flower. Our 

 type may be presented under either of the four numerical forms 

 which have been illustrated. That is, its circles may consist of 

 parts in twos (when it is binary or dimerous), threes (ternary or 

 trimerous), fours (quaternary or tetramerous), or fives (quinary or 

 pentamerous) . The first of these is the least common ; the trime- 

 rous and the pentamerous far the most so. The last is restricted to 

 Dicotyledonous plants, where five is the prevailing number ; while 

 the trimerous flower largely prevails in Monocotyledonous plants, 

 although by no means wanting in the Dicotyledonous class, from 

 which Fig. 277 is taken. 



447. The principal deviations from the perfectly normal or pat- 

 tern flower may be classified as follows. They arise, either from, 



1st. The production of one or more additional circles of one or 

 more of the floral organs (regular multiplication or augmentation) : 

 2d. The production of a pair or a cluster of organs where there 

 21* 



