APHIDES AND ANTS. 97 



Sir Joseph Hooker and Prof. Tyndall have each 

 urged the injury done to discovery by the divorce of 

 imagination from science. " Observation, enthusiasm, 

 and imagination — these three are the prime factors to 

 which is due all excellence in science and art." 

 Doubtless a vivid and educated perception will greatly 

 help a successful generalisation, and often present a 

 working platform for subsequent experiment ; but, on 

 the other hand, the most correct idea may suffer by 

 an expansion under the exuberant fancy of those who 

 love marvels. 



The fact that Aphides are most friendly to such 

 dissimilar insects as Ants has been long known. 

 Goedart, in Reamuer's time, allowed his fancy to run 

 into imaginary conversations between them, relating 

 to such subjects as warning each other against their 

 foes and the like. 



From a similar fancy it is, that the term " vaccse," 

 playfully given by Linneus to those Aphides which 

 yielded their sweet secretions to the solicitation of ants, 

 became " milch cows ; " and the " thrumming " of the 

 ant's antennae on the sides of the abdomen has been 

 since likened to the action of the fingers in ordinary 

 milking ! 



Even Morren saw certain curious analogies between 

 Aphides and Mammifers, and considered that the 

 young Aphides were nourished by the quasi-milk 

 furnished by the nectaries of its mother. 



From Pierre Huber (the son of the historian of 

 bees) we learn that certain continental Ants enclose 

 portions of leaves, largely tenanted by Aphides, in a 

 kind of wall constructed of mud. This enclosure 

 soon afterwards became, in imagination, a paddock for 

 the above milch cows. Again, the cavities below 

 the roots of grasses near ant-hills, in which sub- 

 terranean Aphides feed, are likened to stables or 

 cattle-lairs. 



Huber the younger was aware of the incredulity of 

 his contemporaries ; and that by them his discoveries 



VOL. iv. 7 



