PRELIMINARY DISCOURSES. XX111 



one concrete mass ; in which case the ovary (or young fruit) appears 

 to be below the flower, and is said to be inferior, though it is really 

 above, being within the tube, formed by the cohering sepals, &c., 

 and consolidated therewith. 



The next regular verticil, above the calyx, is called the corolla. 

 The leaflets of this, are usually much more changed than those of 

 the calyx; but even here, we find such various intermediate forms as 

 clearly show that the petals, also, are nothing but modified foliage. 

 In further corroboration of this view, we observe in many plants 

 what seems to be a kind of supernumerary verticil, sometimes situ- 

 ated between the calyx and corolla, and sometimes between the 

 corolla and the stamens ; which supernumeraries are apt to be very 

 curiously modified, and are obviously in a state of transition, either 

 from sepals to petals, or from petals to stamens. These are com- 

 monly called nectaries. The same remarks apply to the two remain- 

 ing regular verticils of the flower, known as stamens, and pistils. 



Singular as it may seem, to the uninitiated, even those organs 

 are now regarded as leaflets, which have reached the final stage of 

 metamorphosis ; for both have been detected in such form and condi- 

 tion as clearly betrayed their foliaceous origin. The reciprocal con- 

 vertibility of petals and stamens, is a fact familiar to every Tyro in 

 Botany. All double flowers so common under high garden culture 

 are familiar examples of staminate verticils being expanded into 

 petals, instead of conforming to the regular law of their nature ; 

 and hence, those exuberant developments so much admired by 

 Florists are considered by Naturalists as accidents, or monstros- 

 ities. 



The pistils, too which comprise the young fruit although less 

 frequently, are subject to a similar imperfection ; and the very ovules, 

 or rudiments of seeds, have been found retrograding, so as to 

 exhibit their tender cotyledons in the form of leafy expansions.* 

 Thus, it appears that the whole of the external organs of a Plant 

 may be fairly regarded as so many leaves, in various successive 



*Each simple pistil may be regarded as & folded leaflet, in the last stage of modi- 

 fication, preparatory to the formation of ovules, and is often termed a carpel, or 

 little fruit. The ovules are usually produced on the margins of the metamorphos- 

 ed leaf, and arc arranged on the placenta (supposed to be formed by the union or 

 decurrence of their pedicels), along the seam, formed by the junction of those 

 margins. When there are several pistils, or carpels, in one flower and those 

 soldered together, we have, of course, a compound fruit, with several cells; i. e. 

 a cell for each carpel. But some of the ovules and even entire cells, or carpels 

 may be, and often are, wholly suppressed, or abortive; thereby impairing the 

 symmetry of the structure but leaving the phenomenon perfectly intelligible. 



