38 



ELEMENTS OF BOTANY. 



FUNCTIONS OF THE FLOWER. 



The only function of the flower which requires our attention is the re- 

 production of the species. 



The manner in which this is accomplished is sufficiently simple, and, to 

 one acquainted with the phenomena of reproduction in animals, readily 

 understood. 



As the flower expands the anthers expel their pollen through pores or 



Fig. 73. — An anther open- 

 ing by pores or chinks at 

 the top. 



Fig. 74.— An anther open- 

 ing by valves. 



Fig. 75.— Anthers depositing pollen directly on the stigma, through 

 which the pollen-tubes are seen passing to the ovules. 



valves opened for this purpose (Figs. 73 and 74). The pollen is either shed 

 directly on the stigma or is carried there by the wind or by insects, and 

 once there it is retained by a glutinous secretion of the stigma (Fig. 75). 



From each pollen-cell (Fig. 76) is then protruded a minute tube, the 

 pollen-tube, which insinuates itself through the stigma, and continuing its 



