THE DRAMA OF LIFE 41 



old idea was that the mother- cuckoo spat them out as she 

 flew around looking for a suitable nest in which to place 

 her egg, and it was also supposed by some that they gave 

 rise spontaneously to singing Cicadas. They have, of 

 course, nothing to do with cuckoos, but they have, in a 

 sense, something to do with cicadas, for they are produced 

 by the larvae of insects, e.g. Aphrophom spumaria, which 

 are related thereto. They are popularly known as frog- 

 hoppers, in allusion to the highly developed jumping 

 powers of the adults. 



The eggs are laid the previous autumn by the mother 

 ' froghopper ' in deep crevices in the bark of willow-bushes 

 or the like ; they hatch in spring, and there emerge small 

 squat larvae with a piercing beak and firmly gripping legs. 

 These probe the leaves and stems of plants and suck up the 

 sugary sap, much as their relatives the green-flies or Aphides 

 do. And just as ' honey- dew ', as it is called, passes out 

 of the food-canal of the green-flies in large quantities and 

 smears the leaves and even falls like drops of rain to the 

 ground, so the surplus sap passes through the frog-hoppers 

 and forms the familiar foam-like ' spit '. The food is very 

 abundant, the larva grows and moults, and grows and 

 moults again, and finally passes into a resting or pupa 

 stage ; its wings grow and other changes of structure are 

 brought about ; it leaves the froth and moults for the last 

 time ; it becomes a full-grown winged insect, and there is 

 no more foam to be seen on the herbage. All the frog- 

 hoppers have grown up. 



The making of the foam which envelops and conceals the 

 larval frog-hopper is of much interest. In the first place, 

 the material is watery sap, slightly changed by passing 

 through the food-canal ; it is exuded at the hind end and 



