38 



ELEMENTS OF BOTANY. 



FUNCTIONS OF THE FLOWER. 



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

 production of thG species. 



T'le manner in -which this is accomplished is sufliciently simple, and, to 

 one acquainted with the phenomena of reproduction in animals, readily 

 understood. 



As the flower expands the anthers expel tlieii* pollen through pores or 



Flo. 73. — An nnthnr opon- 

 ing by i)ores of chiuk.i at 

 the top. 



, FlQ. 71.— An nnthor op'in- 

 ing by viilves 



Fio. 75.— Anthrr- rtcnoslt! r poHen directly on tho Btigmo, through 

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



valves openea for this pui-pose (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). 



Frc^.n each pollen-cell (Fig. 70) is then protruded a minute tube, the 

 poUen-tubc, which insinuates itself through the stigma, and coutiuuiug its 



