IQ2 I '! \MIMGHTS ON NATI'RE 



in raising tin- whole carcass aloft, and hoisting up 

 her astonished neighbour into the air on top of it. 

 It is impossible to watch a nest of ants at work 

 for any length of time without being the spectator 

 of many such comic little episodes. 



I implied above that ants are very fond of honey. 

 But plants by no means desire their attentions ; 

 because, being creeping creatures, guided mainly 

 by the sense of smell, they crawl up the stems of 

 one species after another, indiscriminately, and so 

 do no good in setting the seeds of any particular 

 kind of flower. To baffle them, accordingly, many 

 plants cover their stems with downward-pointing 

 hairs, which prove to the ants as impenetrable an 

 obstacle as tropical jungles to the human explorer; 

 while other sorts set various traps like lobster- 

 pots on their stalks, to catch and imprison the 

 unwelcome visitors. But the wild vetches have 

 a still more curious and instructive habit, shared 

 by not a few other ingenious plants. They buy 

 off the intruders by an organised system of black- 

 mail. Below the flowers intended for fertilisation 

 by flying insects, which flit straight from one 

 blossom to another of the same kind, the vetches 

 put some arrow-shaped guards or stipules, so 

 arranged like barriers on the stem that a prying 

 ant cannot easily creep past them. In the centre 

 of each stipule, however, the plant produces a little 

 black gland, which secretes honey. This honey is 

 a bribe to the marauding ant ; the vetch puts it 

 there in order that the insect, finding its progress 

 toward the flower blocked, may just stop en route 



