THE STAMENS. 



75 



process, which appears necessary in flowering, a high 

 degree of heat is often accumulated during that period. 

 The most remarkable instances of this phenomenon occur 

 where many flowers are inclosed by a spathe, as in the 

 Palms. An English species of Arum affords the most 

 wonderful instance known of this production of heat, 

 which is sometimes so great as to be sensible, and the 

 flower appears as if burning. The common Wake-Robin 

 of our damp woods, which is a nearly allied species, has, 

 it is said, the same habit. 



414. Linnaaus thought that the corolla might serve 

 as wings, to waft the flower up and down, and thus pro- 

 promote the functions of the stamens and pistils ; and 

 others have supposed that its brilliant colors may attract 

 insects for the same purpose, as their honey evidently 

 does. But there must be a deeper design than yet ap- 

 pears in any of these superficial hypotheses. The brilliant 

 hues of the corolla, acted on in a peculiar manner by the 

 solar rays, doubtless promote the absorption of oxygen, 

 and thus assist in decomposing certain substances which 

 have been accumulated in the system, but are at this 

 period rapidly consumed, while their products are retained 

 for the development and nutrition of the ovules, or young 

 plants, after they are separated from the parent. 



CHAPTER XXVI. 



THE STAMENS. 



415. The Essential Okgans op Reproduction, 

 you will remember, are of two sorts, and occupy two 

 whorls or circles, the external set being called Stamens, 

 and the central, or seed-bearing organs. Pistils. The 

 Calyx and Corolla are not essential organs, because fre- 

 quently one, and sometimes both, are absent; but the 

 Stamens and Pistils are essential, because no proper 

 seed can be produced without their presence and joint 

 action. The Stamens, or Fertilizing Organs, form the 

 subject of the present chapter. 



416. Parts of the Stamen. — This organ, considered 

 aside from its contents, usually consists of two parts — 

 the long thread-like process, which is called the Fila- 

 ment, and the rounded knob at its summit, called the 

 Anther. In the Anther is contained the Pollen, or 

 fertilizing granules. The filament is often wanting, and 



Effect on temperature — in what flowers most observable ? Remarkable in- 

 stance. Linnaeua' idea. What did others suppose f What highly probable ? 

 What absorbed — ^under what influence— with what etfect ? What becomes of 

 he hoarded substances— their products. 



General subject What place la the flower do they occupy ? What whorls 

 occupied by the Essential Organs? Parts of the Stamen. Define. Which 



hence the anther is the only essential part. In fig. 1, 

 Plate XXV., a stamen is delmeated, with its filament/, 

 its anther a, and its pollen p. 



417. Elementary Composition — The Anther. — 

 In this part, the tender walls of the cells are thickened 

 and strengthened by delicate fibrous bands, which are 

 very elastic, and sensible to the action of moisture ; and 

 they lengthen or contract, as the anther is dry or wet. 

 These bands become greatly attenuated as they approach 

 that line by which the anther opens for the discharge of 

 its pollen, called the Line of Dehiscence ; and on reach- 

 ing that point, they are completely interrupted. As the 

 anther approaches maturity, the membrane between the 

 bands is gradually obliterated, and only the delicate 

 fibres are left. In these fine threads, the fibrous system 

 of the leaf is represented. 



418. But in the Filament, which is composed inter- 

 nally of a bundle of spiral ducts, is seen the initial pro- 

 cess of the more determined woody system. This bundle 

 is enveloped by the cellular tissue, the outermost layer 

 of which forms a very delicate epidermal membrane, and 

 is still more attenuated at the line of dehiscence. 



419. The Pollen consists of cellular tissue in a 

 peculiar condition. To the naked eye, it appears only a 

 simple powder, usually of a yellowish color; yet seen 

 through the microscope, it is found to consist of a multi- 

 tude of grains, of a highly organized and very beautiful 

 structure, with many variations of form and color, each 

 of which is peculiar and uniform in the species. 



structure of the stamens. 



420. A stamen may be considered as a transformed 

 leaf, with the edges rolled in toward the mid-vein. The 

 filament represents the petiole, and the anther the blade. 

 It is difficult to conceive of this, at least by one view ; 

 but after you have traced the common leaf through all 

 its gradations, from the green sepal to what may be 

 termed its ultimate formations in the stamen and pistil, 

 and thence directly back to the reproduction of green 

 sepals and leaves, it will not be so hard to believe. And 

 this you may do at your leisure, if you wUl study the 

 gradual transformations in almost any double flower, 

 where you will find stamens in every stage of progress. 

 The Rose, in the cultivated or unnatural state, and the 

 White Pond-Lily, whose many petals form an analogous 

 structure in the natural condition, are good subjects for 



essential— not essential — why ? Elementary composition of the Antber- Fila- 

 ment — Pollen. What is the Line of Dehiscence ? How does Pollen appear to 

 the naked eye — how under the microscope ? What may a Stamen be consider- 

 ed? What part does the filament represent — the anther? How proved? 

 Describe the process. 



