GENERAL CONSIDERATIONS. 127 



reproduction, also lay eggs. The former are only additional 

 means employed by nature to secure the perpetuation of the 

 species, super-added to the usual method of propagation. 



Now plants have sexes or sexual organs as well, as ani- 

 mals. The female sexual organs in plants are called 



Fig. 24. Fig. 25. 



Fig. 21. A pistil exhibited in section to show the young ovules d, attached to 

 the placenta or walls of the ovary cs, and contained within its cavity, c. The 

 stigma or summit of the pistil, to which the pollen grains adhere when fertiliza- 

 tion takes place. &. The style of the pistil, through the loose cellular tissue of 

 which the pollen tuhes descend in their passage to the ovary.' 



Fig. 25. A stamen. Its filament or support a, and its anther d, discharging 

 the fecundating matter or pollen. 



carpels. The pistil which consists of stigma, style, and ger- 

 men, is only a fully developed cai^el. The male sexual 

 organs are named stamens, the anthers of which contain 

 the pollen or fecundating matter. The stamens and car- 

 pels are the essential organs of reproduction in plants, since 

 it is by the mutual action of these bodies that the vegetable 

 embryo is formed. 



The ovules contained in the germen or ovary are the 

 bodies which after impregnation become seed. Their exis- 

 tence may be verified by making a section of the germen, 

 whilst the flower is still in the bud, and before the anther 

 cells have been ruptured,- and, in this condition, they un- 



