I.] 



MALVA. EPILOBIUM. 



sylvestris (Fig. 7) and Malva rotundifolia (Fig. 8) 

 which grow in the same localities, and therefore must 

 come into competition, are nevertheless nearly equally 

 common. 



In Malva sylvestris, however (Fig. 9), where the 

 branches of the stigma are so arranged that the plant 

 cannot fertilise itself, the petals are large and conspi- 

 cuous, so that the plant is visited by numerous insects ; 

 while in Malva rotundifolia, the flowers of which are 

 comparatively small and rarely visited by insects, the 



FIG 9. Stamens and stigmas of 

 Malva sylvestris. 



FIG. 10. Ditto of Macva rotundifolia- 



branches of the stigma are elongated, and twine them- 

 selves (Fig. 10) among the stamens, so that the flower 

 readily fertilises itself. 



Another interesting case is afforded by the genus 

 Epilobium. Epilobium angustifolium has large pur- 

 plish flowers in conspicuous heads (Fig. n), and is 

 much frequented by insects; while E. parvifloruvt 

 (Fig. 12) has small solitary flowers and is seldom 

 visited by insects. Now in the former species their 

 visits are necessary, because the stamens ripen and 



