i8 



ARISTOLOCHIAARUM. 



[CHAP 



interesting case is that of the genus Aristolochia. The 

 flower is a long tube, with a narrow opening closed by 

 stiff hairs which point backwards, so that it much re- 

 sembles an ordinary eel-trap. Small flies enter the 

 tube in search of honey, but from the direction of the 

 hairs it is impossible for them to return. Thus they 

 are imprisoned in the flower, until the stamens have 

 ripened and shed their pollen, by which the flies get 



FIG. 13. Diagrammatic section of Arum, ft, hairs ; a, anthers ; sf, stigmas. 



thoroughly dusted. Then the hairs of the tube shrivel 

 up, thus releasing the prisoners, which carry the pollen 

 to another flower. 



A"-ain, in our common Arums the Lords and 



iO r 



Ladies of village children the well-known green leaf 

 incloses a central pillar, near the base of which are 

 arranged a number of stigmas (sf, Fig. 13), and above 



