138 MINUTE MARVELS OF NATURE 



leaf when searching for aphides in an apparently 

 reckless manner. Then it is most interesting and 

 curious to see one of these strange grubs suddenly, 

 on meeting with an aphis, pick it up clear from 

 the branch, and then stand upright on its tail end 

 away from the branch, and remain in this attitude 

 while it devours it. Thus one juicy fly after 

 another is taken, sucked dry, and its skin cast 

 aside so rapidly that, in the course of an hour or 

 so, a branch that was loaded with aphides becomes 

 practically clean. And this is only one of the 

 enemies of the green-fly. The pretty lacewing- 

 fly also places its dozen or so of curious stalked 

 eggs so familiar on lilac and other trees along 

 the leaves and branches, from which the larvae 

 hatch and drop down to assist in devouring the 

 aphides, protecting themselves by covering their 

 bodies with their victims' skins, which they impale 

 on hooks or spines on their backs. Thus to all 

 appearance each becomes a portion of the stem 

 itself covered with aphides as it moves about 

 " seeking whom it may devour," and so it disguises 

 itself from its own enemies. 



In a later chapter I shall consider some 

 parasites that trouble or benefit animal life ; 

 and it may prove interesting here to glance at 

 a few of the eggs of these degraded animals. 



Bird parasites present some remarkable forms in 



