YO STA]!>rENS. 



"We then resort to position, and consider -whether the stamens are inserted upon 

 the calyx or the receptacle, thus furnishing an eleventh and a twelfth class. 



Inequality in the length of stamens, when they are either four or six, furnishes U3 

 with a thirteenth and fourteenth class. 



The cotmection or union of stamens gives us the fifteentli class, where the frla 

 ments of the stamens are united in one set ; the sixteenth class, where they are in 

 two sets ; the seventeenth, where the anthers of the stamens are united. 



The three remaining classes of phenogamous plants are distinguished by the 

 position of the stamens with rcsj)ect to the pistils. In the eighteenth class the sta- 

 mens stand on the pistil ; in the nineteenth the stamens and pistils are on separate 

 flowers on the same plant ; in the twentieth they are on separate plants ; and in 

 the twenty-first they are invisible, or wanting. 



T8. Parts of the Stamen. — ^Tlie Filament is so called from 

 ■filitm^ a thread. It consists of a thin einderinis^ cellular tissue^ 

 and sjpiral vessels ; the latter extend through the whole length, 

 and terminate at the nnion of the filament with the anther. 

 Filaments vary in their form ; some are long and slender, as in 

 the pink ; others are short and -thick, as in the tulip. They 

 are usually smooth, but in the mullein they are bearded, in the 

 spider-wort they are covered with down. In most cases a fila- 

 ment supports bi*t one anther, but sometimes it is forked, and 

 bears two or more; in some instances many filaments have 

 but one anther. "When the filaments are inclosed in the tube 

 of the corolla, they are said to be inserted ; when they extend 

 out of it, exserted. Li some cases the filament is wanting, and 

 the anther is sessile, or immediately attached to the corolla. 



a. In double flowers, the stamens, wliich seem to be intimately connected with 

 the parts of the corolla, are changed to petals. This is the effect of cultivation, 

 which, by affording the stamens excess of nourishment, causes them to expand and 

 thus assume the form of petals. In some double flowers almost every trace of the 

 stamens disappears ; in others, it is easy to perceive the metamorphosis which they 

 have undergone, as they retain something of their original forms. In double flowers 

 the anthers usually disappear, which shows that the filaments have absorbed the 

 nourishment. In double roses some stamens appear entirely changed, others re 

 tain something of their form, and others remain perfect. When all the stamens 

 disappear, no perfect fruit is produced. On account of this degeneration of the 

 stamens, cultivated flowers are not usually so good for botanical analysis as wild 

 ones. The single flower exhibits the number of parts which nature has given to it. 

 The rose in its native state has but five petals. 



Y9. The Anther is supposed to be formed of the lamina of 

 the leaf; it consists of cells containing minute particles, called 

 pollen^ which in the mature state of the flower is thrown out by 

 the bursting of the cells. The lobes of the anther may be con- 

 sidered as formed by the two halves of the lamina of the leaf, 

 the midrib being represented by the connective^ and the mar- 

 gins' by the suture, or line by which the lobes of the anther 

 usually open. That part of the cellular tissue of the leaf next 

 the cuticle is changed into a fibrous tissue, while the grains 

 of pollen are transformed from the remainder of the tissue. 



78. Filament — a. Stamene changed to petal*. — 79. Structure of the anther. 



