76 JJOTANY FOR EEGINNEUS. [ Ch. XII] 



stand on the pistil; hi the nineteenth, the stamens and pistiL 

 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 so 

 called from fiiuin, 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 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, exserted. 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 ihe 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 to it. The Rose in its 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 analysis? 



