ORGANS OF REPRODUCTION. 



65 



356. All these floral organs, unlike as they are to 

 each other, and to the common Leaf of the plant, are yet 

 only varied transformations of that organ. That they 

 are really transformed leaves, is clearly shown by seve- 

 ral well-known facts. The transition from common 

 leaves to sepals is generally very clear ; while that from 

 the sepals to petals is, in many flowers, equally obvious, 

 and especially in those where there is a colored perianth, 

 as in the Tulip, and others of the Lily tribe ; certain 

 parts of the divisions being almost always marked with 

 the green color and texture of the calyx, while the re- 

 mainder exhibit the brilliant colors and finer texture of 

 the corolla. 



357. By excessive nutriment in cultivation, and 

 other unnatural stimuli, the stamens, and often the 

 pistils, are changed to petals, producing what are called 

 DOUBLE flowers. The Rose, Hollyhock, Peony and 

 Dahlia, are familiar instances ; and in these flowers you 

 may often see the various stages of transition ; for you 

 will always observe, as you approach the centre of the 

 flower, that the petals become narrower, and exhibit 

 various foldings, until, by almost imperceptible changes, 

 they pass into the stamens and pistils. Thus you will 

 find by observation, that metamorphoses, or interchange 

 of forms are of frequent occurrence in the Floral world. 



358. The most common of these transformations is 

 that of the stamens and pistils into petals. But not 

 unfrequently the order is reversed, and the transformed 

 organs show a more decided inclination to revert to their 

 primitive type. The Rose sometimes produces a second 

 bud from the bosom of its flower. The Mourning Bride 

 often exhibits like deformities, putting forth from its 

 expanded blossom a stalk, with the flower and all its 

 parts, though not often colored like the first. The pro- 

 duction of a leafy branch is not very uncommon in the 

 flowers of the Apple and Pear ; and even the FKUIT of 

 the latter, when the transformation had reached its last 

 remove, has manifested a sudden resolution to return to 

 the original type, in the production of a leafy branch from 

 its summit. In all these cases, there is an obvious effort 

 to continue the axis of growth. The flower of the Clover, 

 and some other plants, will put forth green leaves from 

 its petals ; and in the Double-flowering Cherry, the pistils 

 often revert to leaves. But these changes are innumer 

 able. Enough has been said to show that there is no 



Of what are all these organs transformations? Most common of these. 

 How are the essential Organs in DOUBLE FLOWEES ? Describe the transitions, 

 and give examples. "What of common occurrence? Which are the Essential 

 Organs? Why so called? Instances of reversed transformation. What effort 

 does all this indicate what does it show ? Why ? What gives an impression 

 of wonder ? What do we go on finding what led to seek what in the same 

 



absolute line of distinction between their elementary 

 conditions, since they must have one common origin, or 

 they would not, and could not, all revert to one common 

 type. 



359. Nothing, perhaps, has ever impressed the young 

 student with a higher degree of wonder than the continual 

 occurrence of the same number in any particular part of 

 a flower. Thus, if any given flower has five, or ten, or 

 four stamens, millions of individuals of the same 

 species, almost as a matter of certainty, will have the 

 same. We go on, finding yet more complex principles 

 of arrangement, exhibiting a mathematical uniformity; 

 and thus we are led to seek for LAWS, to which external 

 facts must be subservient. Finding so general a uniformity 

 of numbers in the same parts of a flower, we begin to 

 compare the different parts; and here, although they 

 are not often perfectly uniform, yet there is always a 

 determination to certain numbers ; and this fact points 

 to a perfect type, which may have been disturbed by 

 some accident, and, by a recurrence of the same circum- 

 stances, has been inherited, or perpetuated in the species. 

 There is a certain symmetry often observed in flowers, 

 when their several whorls present the same numbers, or 

 multiples of the same, as in the Flax, which has five 

 sepals, five petals, five stamens with the rudiments of 

 five undeveloped ones five pistils ; and its seed-vessel is 

 five celled. But there are several causes which disturb 

 this symmetry, so that in very few cases the relation of 

 number is complete. The principal of these are Abor- 

 tion, Suppression, Coalescence, Adnation, Chorisis, Regu- 

 lar Multiplication, and Irregularity of Form. 



360. ABORTION is the imperfect development of any 

 part, as in the sterile stamens of the Parnassia. 



361. SUPPRESSION is the entire absence of any part ; 

 as in the nondevelopment of the fifth stamen in the Fig- 

 wort tribe. 



362. COALESCENCE is the union of parts in the same 

 whorl, as that of the stamens in the Pea and Sun-flower 

 tribes. 



363. ADNATION is the union of parts of different 

 whorls. It gives the appearance of one organ growing 

 out of another, instead of its normal basis the receptacle, 

 as when the stamens appear inserted on the corolla, or 

 growing out of the pistil, or the calyx is adherent to the 

 corolla. When all the several whorls occupy their true 



parts what compare? What general laws of symmetry observed ? Instance 

 of complete symmetry. Is this common ? Principal causes that disturb sym- 

 metry. Define Abortion, Suppression, Coalescence, Adnation, Chorisis, Regu- 

 lar Multiplication, Irregularity of Form. Difference between Adnation and 

 Coalescence Abortion and Suppression. When are the stamens and pistils 

 generally regular and symmetrical ' 



