20 ON FLOWERS AND INSECTS. [LECT. 



(Fig. 14) in the neck of the tube, the other under the 

 arched hood, The lower anther, moreover, is more or 

 less rudimentary. Now when a bee comes to suck the 

 honey, it pushes the lower anther out of the way with 

 its head ; the result of which is that the connective swings 

 round, and the upper fertile anther comes down on to 

 the back of the bee (Figs. 15 and 18), and dusts it with 



FIG. 17. Stamens in their natural FIG. 18.- Stamens when moved 



position. by a Bee. 



honey, just at the place where, in an older flower (Fig. 

 16) it would be touched by the stigma st. 



At first sight, it may seem an objection to this view 

 that some species as, for instance, the Common Antir- 

 rhinum, which, according to the above given tests ought 

 to be fertilised t>y insects, is entirely closed. A little con- 

 sideration, however, will suggest the reply. The Antir- 

 rhinum is especially adapted for fertilisation by humble 

 bees. The stamens and pistil are so arranged that 

 smaller species would not effect the object. It is there- 

 fore an advantage that they should be excluded, and 

 in fact they are not strong enough to move the spring. 

 The Antirrhinum is, so to say, a closed box, of which 

 the humble bees alone possess the key. 



The Common Heath (Erica tetralix) offers us a very 

 ingenious arrangement. The flower is in the form of an 



