L] THE ARUM. THE DEADNETTLE. 17 



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 

 (h). When the anthers 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. 



Now let us return to our White Dead- 

 nettle and see how far we can answer the 

 questions which I began by asking. 



In the first place, the honey attracts 

 insects. If there were no honey, they 

 would have no object in visiting the 

 flower. The bright color is useful 

 in rendering the flower conspicuous. 

 The platform serves as an alighting FIG> 13 ._ Diagram . 

 stage for bees. The length of the tube atic s \ cti( ^ 11 . of 



Arum, h, hairs : 



has reference to that of their proboscis, a \ anthe rs; *t, 



stigmas. 



and prevents the smaller species from 

 obtaining access to the honey, which would be injurious 

 to the flower, as it would remove the source of attraction 

 for the bees, without effecting the object in view. The 

 upper arch of the flower protects the stamens and pistil, 

 and also presses them firmly agaiust the back of the 

 bee. So that, when the bee alights on the stage and 

 pushes its proboscis down to the honey, its back comes 

 into contact with them. The row of small hairs at 

 the bottom of the tube prevents small insects from 

 creeping down the tube and stealing the honey. Lastly, 

 the small processes on each side of the lower lip are 



S.E. 



