ii.] ANTS AND PLANTS. 37 



Moreover, if larger flowers were visited by ants, not 

 only would these deprive the flowers of their honey, 

 without fulfilling any useful function in return, but 

 they would probably prevent the really useful visits 

 of bees. If you touch an ant with a needle or a 

 bristle, she is almost sure to seize it in her jaws ; and 

 if bees, when visiting any particular species, were liable 

 to have the delicate tip of their proboscis seized on by 

 the horny jaws of an ant, we may be sure that such a 

 plant would soon be deserted. 



On the other hand, we know how fond ants are of 

 honey, and how zealously and unremittingly they search 

 for food. How is it, then, that they do not anticipate 

 the bees, and secure the honey for themselves ? Kerner 

 has recently published a most interesting memoir on 

 this subject, and has pointed out a number of in- 

 genious contrivances by which flowers protect them 

 selves from the unwelcome visits of such intruders. 

 The most frequent are the interposition of chevaux 

 de frise, which ants cannot penetrate, glutinous parts 

 which they cannot traverse, slippery slopes which they 

 cannot climb, or barriers which close the way. 



Firstly, then, as regards chevaux de frise. In some 

 respects these are the most effectual protection, since 

 they exclude not only creeping insects, but also other 

 creatures, such as slugs. With this object, it will be 

 observed that the hairs which cover the stalks of so 

 many herbs usually point downwards. A good example 

 of this is afforded, for instance, by a plant, Knautia dip- 

 sacifolia (Fig. 34), allied to our Common Blue Scabious. 

 The heads of the Common Carline (Carlina vulgar is) 

 (Fig. 36), again, present a sort of thicket, which must 



