160 HONEY-DEW 



no doubt, by the faint perfume exhaled from the nectar 

 above them. Smelling their road cautiously to the ends 

 of the branches, they soon reach their own particular 

 aphides, whose bodies they proceed gently to stroke with 

 their outstretched feelers, and then stand by quietly for a 

 moment in happy anticipation of the coming dinner. 

 Presently, the obedient aphis, conscious of its lawful 

 master's friendly presence, begins slowly to emit from two 

 long horn-like tubes near the centre of its back a couple of 

 limpid drops of a sticky pale yellow fluid. Honey-dew our 

 English rustics still call it, because, when the aphides 

 are not milked often enough by ants, they discharge it 

 awkwardly of their own accord, and then it falls as a sweet 

 clammy dew upon the grass beneath them. The ant, 

 approaching the two tubes with cautious tenderness, 

 removes the sweet drops without injuring in any way his 

 little protege, and then passes on to the next in order of 

 his tiny cattle, leaving the aphis apparently as much 

 relieved by the process as a cow with a full hanging udder 

 is relieved by the timely attention of the human milkmaid. 

 Evidently, this is a case of mutual accommodation in the 

 political economy of the ants and aphides : a free inter- 

 change of services between the ant as consumer and the 

 aphis as producer. Why the aphides should have acquired 

 the curious necessity for getting rid of this sweet, sticky, 

 and nutritious secretion nobody knows with certainty ; but 

 it is at least quite clear that the liquid is a considerable 

 nuisance to them in their very sedentary and monotonous 

 existence a waste product of which they are anxious to 

 disembarrass themselves as easily as possible and that 

 while they themselves stand to the ants in the relation of 

 purveyors of food supply, the ants in return stand to them 

 in the relation cf scavengers, or contractors for the removal 

 of useless accumulations. 



