STAMENS. 
95 
are inserted upon the calyx or not, thus distinguishing an elev- 
enth and a twelfth class. Inequality in the length of stamens, 
considered with respect to number, furnishes us with a thirteenth 
and fourteenth class. The connection or union of stamens gives 
us the fifteenth class, where the filaments of the stamens are 
united in one set ; the sixteenth class where they are in two 
sets ; the seventeeth where the anthers of the stamens are uni- 
ted. The three remaining classes of plienogamous plants are 
distinguished by the position of the stamens with respect to the 
pistils. In the eighteenth class the stamens stand on the pistil ; 
in the nineteenth the stamens and pistils are on separate flowers 
on the same plant ; and in the twentieth they are on separate 
plants. 
We will now proceed to the parts of the stamen. The stamen 
is divided into two parts th ejilament and anther. 
The Filament , is so called from filum , a thread. 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 mullen they are bearded, in the spider -wort, 
(Tradescantia) they are covered with down. In most cases a fila- 
ment supports but 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 enclosed in the tube of the co- 
rolla they are said to be inserted , when they extend out of it 
exserted. In some cases the filament is wanting, and the anther 
is sessile, or immediately attached to the corolla. 
In double flowers the stamens which 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 swell out, and thus as- 
sume the form of petals. In some double flowers almost every 
trace of the stamens disappears ; in others, it is very easy to 
perceive the metamorphosis, which they have undergone, as 
they retain something of their original form. The anthers usu- 
ally disappear, which shows that the filaments have absorbed all 
the nourishment. In many double flowers, roses especially, we 
can see the change as it takes place, some stamens entirely 
changed, others retaining something of their form, and others 
still 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. 
In length — In connexion — In position with respect to the pistil — Parts of 
the stamens — Filament — Stamens changed to petals — 
