11 6 COLIN CLOUT'S CALENDAR. 



leafy nectaries is now being eagerly attacked by small 

 black ants, who are greedily sipping up the honey as 

 fast as it exudes. There cannot be much doubt that 

 that is the very purpose for which the nectaries are put 

 there. Ants are known to be terrible honey thieves ; and 

 they are perpetually trying to get at the store of sweets 

 which the plant has laid by in the base of its flower to 

 allure the fertilising bees. I^ut any flower which is thus 

 rifled will never be visited or impregnated by insect 

 visitors ; and so those plants whose structure aids them 

 by any chance trick or sport in baffling the ants will be 

 the only ones that can set their seeds and become the 

 parents of future generations. Hence, almost all honey- 

 bearing flowers have inherited some peculiar modification 

 of structure which enables them to set at defiance all such 

 creeping marauders. Many of them have stalks covered 

 with long hairs — often star-shaped at the end (as one can 

 see even through a little pocket lens), or tipped on top 

 with small, round, sticky glands. Now, there is nothing 

 that bothers ants so much as hairs : they seem as in- 

 capable of getting through them as a cow is incapable of 

 getting through a thickset hedge. Other plants, again, 

 secrete a gummy exudation on the stem, in which the 

 wretched foragers get clogged and slowly killed, like flies 

 on a plate of treacle. But the vetch has few hairs and 

 no sticky glands, so it tries to bribe the ants by throwing 

 them a sop instead. The nectaries on the stipules dis- 

 tract them from the flowers ; and if you watch you will 

 see that the ants never mount the slender flower-stalks 

 at all, but go straight up the main stem from one such 

 extra-floral honey-gland to another. No doubt they 

 never discover the existence of the real flowers at all. 



