324 SCIENCE FROM AN EASY CHAIR 



Another curious production of the aphides common 

 on the leaves of elms and other trees infested by them is 

 known as " honey-dew." It is sticky and sweet, and was 

 supposed by old writers to have distilled from the stars, or 

 otherwise to have dropped from heaven. It is this sweet 

 secretion which has led to the establishment of a most 



FIG. 60. An ant "milking" a " plant-louse "or "green-fly" for honey- 

 dew. The drop of honey-dew is seen exuding from one of the two long 

 tubes or spouts (called " cornicles ") on the back of the plant-louse at a. 

 These spouts are seen at the hinder part of the body in the drawings of 

 the hop-louse (Figs. 55 to 59). The ant is causing the aphis to pour 

 out its honey-dew (in fact "milking" it) by "drumming" on the body 

 of the plant-louse with its clubbed antennae, and has taken the drop of 

 honey-dew between its jaws. This drawing was made from life by the 

 late Mr. Buckton, F.R.S., a great student of these creatures. The ant 

 is that kind known as Myrinica rubra. The plant-louse is the Aphis 

 sambucim blight of the elder-tree. 



curious friendship between ants and aphides, or plant-lice. 

 It has long been known that an ant will approach an 

 aphis, and tickle it, when at once the aphis exudes from 

 its cornicles (see Fig. 60) a drop of sweet honey-dew, 

 which the ant swallows just as a man may milk a cow 

 and drink the milk. And the resemblance goes further, 

 for the ants take possession of certain aphides, and keep 



