POLLEN. 35 



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

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

 corolla, or the calyx, constituting the androecium. 



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

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

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

 tial. 



67. The FILAMENT (Lat. filum, a tlnead) 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. Wlien 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- 

 formed 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 apeitm-e (pore) at 

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



b. The connectile is usuallj^a mere pi'olongation 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. 



69. In regard to the modes of attaclmient between the anther and the filament, 

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



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



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

 lateral ; as in the Anemone, water-Uly. 



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

 lightly 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 (turned 

 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 former are seen in the violet ; of the latter in the lai-kspur. 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, 



