76 BOTANY FOR BEGINNERS. [Ch. XHI. 
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. Lastly, in Cryptogamous plants, they 
are invisible. 
312. We will now proceed to the parts of the stamen ; these 
are two. The filament and anther. The filament, is sw 
called from filum,a thread. Filaments vary in their form; 
some are long and slender, as in the pink; others are short and 
thick, asin the tulip. They are usually smooth, but in the Mul- 
lein they are bearded, in the Spider-wort they are covered with 
down. In most cases a filament supports but one anther, but 
sometimes it is forked and bears two or more; in some in- 
stances, many filaments have but one anther. When the fila- 
ments are enclosed in the tube of the corolla, they are said to 
be inserted, when they extend out of it, erserted. In some 
cases the filament is wanting, and the anther is sessile, or im- 
mediately attached to the corolla. 
313. In double flowers, the stamens, which seem to be inti- 
mately 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 assume the form of petals. In some double flowers almost 
every trace of the stamens disappears; in others, it is very easy 
to perceive the change which they have undergone, as they re- 
tain something of their original form. The anthers usually 
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 being entirely 
changed, others retaining something of their form, and others 
still perfect. When all the stamens disappear, no perfect fruit 
is produced. — 
314. On account of this change in 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 toit. The Rose inits native state has but five 
petals. 
312. What is said of the filament? 
313. What causes double flowers ? 
314. Are cultivated flowers usually the best for arialysis? 
