108 



THE FLOWER 



/- 



« h 



143. a, a stamen ; p, pollpn snr: c, 

 connective; /", tilameiu ; h, 

 a stamen with the anther 

 cut through at the time of 

 maturity". 



203. The pollen-bearing organ is the stamen (Fig. 143) 



Its parts are the stalk, called 

 the filament, and the anther, 

 containing the pollen in 2) oil en 

 sacs. In the j-oiing condition 

 of the stamen four longitudi- 

 nal pollen sacs are found. 

 The whole mass of tissire 

 tilling these sacs is finally con- 

 verted to pollen. At matu- 

 rity, if not before, the wall 

 between the two cavities on 

 the same side of the anther 

 commonly disapj^ears, leaving 

 a single pollen sac in either 

 half-anther. The middle pai-t 



or axis of the anther between the two pouches thus formed 

 is the connective. 



204. The pollen sacs open for the liberation of the pollen 

 usually by a slit along the groove running down each side 

 of the anther; in Pyrola and other members of the Heath 

 family, by terminal pores (Fig. 144) ; 

 and in the Barberr}^ by uplifting- 

 valves (Fig. 145). And other modes 

 of dehiscence occur, suited to the 

 various means by wdiich the pollen 

 is to reach its destination. 



205. The number of stamens is 

 often large, as in the wild Rose, the 

 Ijuttercup, the ^Magnolia, and the 

 Water Lil)-. In a few species there 

 is but one. Generally speaking, the 

 number is small, not more than ten; 

 and, when small, usually definite for 

 each species. For example, most grasses have three sta- 

 mens, most [Mints four, the Violets five, and the true 

 Lilies commonly six. Each jDollen sac produces a vast 

 number of pollen grains. And when the flowers borne 



14i, 145. Stamens: 144, of 

 Pyrola, the autlicr 

 opening by terminal 

 pores; 14."), of Bar- 

 berry, the anilier 

 opening by uplifting 

 valves. 



