88 :fi5otan^ 



the flower. The purjDose of this bidding for insect 

 visitors will be explained in Chapter VII. 



The corolla is composed of two parts, banner and 

 claw. The banner is the wide part; the claw holds 

 fast to the receptacle. The stamen consists of two 

 parts, the filament and anther. The filament is the 

 stem part of the stamen ; it may be long, short, or 

 wanting altogether. The anther is a little box, 

 usually oblong, composed of two lobes and opening 

 in the centre. Within the anther grows a fine yellow 

 dust called pollen. Sometimes the pollen is not 

 yellow but dark-brown or reddish. When the pollen 

 is ripe the anther opens and the pollen flies out. 

 Pollen grains can only be examined with a micro- 

 scope. We shall find that eacli grain is a little sac, 

 full of liquid, in wdiich is held a constantly moving 

 atom ; this atom is the life point of the flower. 



The pistil has three parts. At the base is a little 

 box called the ovary ; then comes the stjde, a hollow 

 tube bearing on its top the stigma, a soft, sticky 

 cushion. When there is no style the stigma is fixed 

 directly upon the ovary. The ovary is full of little 

 ovules or egglets that will presently become seeds. 

 These ovules cannot develop into seeds unless the 

 pollen reaches them. 



The grains of pollen must first reach the sticky 

 surface of the stigma; being held fast there, they 



