134 



On Flowers and Insects, 



the pollen is ripe. The pollen must therefore be 

 brought by insects, and this is effected by small 

 flies, which enter the leaf, either for the sake of 

 honey or of shelter, and which, moreover, when 

 they have once entered the tube, are imprisoned 

 by the fringe of hairs (//). When the anthers 



Fig. 36. COMMON ARUM. Diagrammatic Section. 

 h, hairs ; a, anthers ; st, stigmas. 



ripen, the pollen falls on to the flies, which in their 

 efforts to escape get thoroughly dusted with it. 

 Then the fringe of hairs withers, and the flies, thus 

 set free, soon come out, and ere long carry the 

 pollen to another plant. 



7. Now let us return to our White Deadnettle, 



