180 Sir Johi Luhhoch [May 9, 



analogy to the three great phases — the hunting, pastoral, and agricul- 

 tural stages — in the history of human development. 



When I first began keeping ants, I surrounded the nests by moats 

 of water. This acted well, but the water required continually renew- 

 ing, especially, of course, in summer, just when the ants were most 

 active. At length, however, in considering the habits of ants and 

 their relation to flowers, another plan suggested itself to me. The 

 hairs by which plants are clothed are of various forms, and fulfil 

 various functions ; one is, I believe, to prevent ants and other creeping 

 insects from climbing up the plants so as to obtain access to the 

 flowers, and thus rob them of their honey ; for though ants are in 

 some respects very useful to plants, they are not wanted in the 

 flowers. The great object of the beauty, scent, and honey of flowers, 

 is to secure cross fertilization ; but for this purpose winged insects 

 are almost necessary, because they fly readily from one plant to 

 another, and generally confine themselves for a certain time to the 

 same species. Creeping insects, on the other hand, naturally would 

 pass from one flower to another on the same plant; and as Mr. 

 Darwin has shown, it is desirable that the pollen should be brought 

 from a different plant altogether. Moreover, when ants quit a plant, 

 they naturally creep up another close by, without any regard to 

 species. Hence, even to small flowers, such as many cruciferas, com- 

 positae, saxifrages, &c., which, as far as size is concerned, might well 

 be fertilized by ants, the visits of flying insects are much more advan- 

 tageous. Moreover, if larger flowers were visited by ants, not only 

 would they 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 plant, were liable to have the delicate tip of their pro- 

 boscis seized on by the honey jaws of an ant, we may be sure that 

 such a species of plant would soon cease to be visited. 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 ? This is 

 guarded against in several ways. Some plants are covered with 

 glandular hairs, which make them so sticky that ants do not attempt 

 to walk up them. Some are said to be so slippery that ants cannot 

 do so. Some flowers are closed so that ants cannot get into them. 

 But the commonest protection, perhaps, of all is provided, as I have 

 mentioned, by a clothing of downward-pointing hairs, making a sort 

 of cJieveiix de frise which effectually stops the ants. It occurred to 

 me, therefore, that instead of water I might use fiu', arranged so that 

 the hairs pointed downwards. This I have found to answer per- 

 fectly, and I mention it specially because the same arrangement may 

 perhaps be found practically useful in hot climates. 



When I last had the honour of addressing you, I mentioned 

 various experiments which proved that ants remembered their friends 



