SG 



Elementary Work in Botany. 



or quite alike, the anther is innate. Observe carefully how 

 the anther cells open to let the pollen out. Which open by 

 splitting lengthwise along the face? Which by splitting 

 along the edges? Do any discharge the pollen through 

 holes at the top? Some stamens face the pistil (inward). 

 These have introrse anthers. Those with their backs to 

 the pistil are extrorse. Take a stamen from each kind of 

 bud and compare with one from the flower. Have you. any 



flowers with two kinds of sta- 

 mens? Are any sterile ? Draw 

 all those taken from the buds, 

 representing a profile and a face 

 view of each kind. Also draw a 

 few which are discharging pol- 

 len. Do any discharge pollen 

 in the bud? Label your draw- 

 ings in this way : (a) Mustard 

 stamen one of the long ones 

 in the bud. Anther adnate 

 and introrse. (b) Same in open 

 flower. Anther extrorse by a quarter twist of the filament; 

 pollen escaping by slits. Why do the four long stamens of 

 mustard standing as high as the stigma turn so as to 

 face away from the center? The short pair have introrse 

 anthers in the bud, and they remain facing the pistil in the 

 open flower. Why do they not also turn away from the 

 pistil? Do you find any anthers with four cells? Are 

 there any stamens with appendages to the filaments or the 



Fig. 65. A. a. Flower of a common 

 shrubby lupine. 6. The same with the 

 upp^rand side petals removed showirg 

 the united pair of long-clawed petals 

 which enclose the united stamens and 

 pistil. B. a. Same with all the peta^ 

 removed showing 5 empty anthers. 

 b. Stamens as they appear in the bud, 

 with the anthers all full. The short 

 stamens of the bud become the long 

 stamens of the flower, c and d. Anthers 

 magnified. 



