POLLEN. 35 



65. The STAMENS are those thread-like organs, seen in the 

 midst of the flower, situated around the pistils and within the 

 corolla, or the calj-^x, constituting the andnrcium. 



C6. The stamen (Fig. 4, No. 3) consists of three distmct 

 parts; namely, the filament, a; the anther, h; and the pollen, c. 

 The filament is sometimes wanting, the two latter are essen- 

 tial. 



67. Tlie FILAMENT (Lat. filum, a thread) is the stem, sup- 

 porting the anther at or near its top, and is analogous to the 

 stem of a leaf, or to the claw of a petal. When it is wanting, 

 the anther, like a leaf or a petal in a similar case, is said to be 

 sessile. 



68. The ANTHER is generally situated at the summit of the 

 filament, and is composed of two parallel lobes or cells, con- 

 nected to each other and to the filament by the connectile. It is 

 analogous to the blade of the leaf, each half blade being trans- 

 fomied into a lobe, and the midrib into the connectile. 



a. Each cell of the anther usually opens by a longitudinal fissure, called the 

 dehiscence, but sometimes, as in the potato, Pyrola, &c. by an aperture (pore) at 

 the summit. In the Polygala, mallow, &c. the two cells are reduced to one. 



b. The connectile is usually a mere prolongation of the filament tenninating, 

 not at the base, but at the summit of the anthers. In some cases it is prolonged 

 above them, into a sort of appendage, as in the violet, silk-weed, &c. 



c. The anther is sometimes wanting, and the filament in such cases cannot 

 constitute a stamen, but is said to be abortive, or sterile. 



09. In regard to the modes of attachment between the anther and the filament, 

 we find the following variations ; the anthers are said to be, 



1. Lmate, when they are attached to the filament by the base of the connectile. 



2. Adnate, when they are attached to the filament by then- back, so as to appear 

 lateral ; as in the Anemone, water-Uly. 



3. Versatile, when fixed by a single point to the connectile, from which they 

 lighth' swing ; as in the grasses. 



4. When the anthers are attached to the inside of the filament, or connectile, so 

 that the line of dehiscence faces the pistils, they are called introrse (tumed 

 inward). But when they are attached to the outside of the connectile, so that the 

 dehiscence faces the petals, they are called extrorse (turned outward). Examples 

 of the foi-raer are seen in the violet ; of the latter in the larkspur. These distinc- 

 tions are of importance, as will hereafter be seen. 



70. The POLLEN is, in appearance, a small, yellow dust, con- 

 tained in the cells of the anther. When viewed with a micro- 

 scope, it appears to consist of grains (granules) of various forms, 

 4 



