MAY-FLIES AND THEIR NEIGHBOURS 219 



oblong in shape, with a narrowed point at the top, 

 and arranged standing on their ends. Generally 

 there are many hundred eggs in each cluster. 

 Sometimes the eggs are placed several yards 



Fig. 144. An alder-fly. x 3 diameters 



away from the pond, which makes it extremely 

 awkward for the young larvse when hatched, for 

 their aquatic instincts at once manifest themselves. 

 However, they proceed with all possible speed to 

 the nearest water-course and so drift down to the 

 ponds, and at once become denizens of the muddy 

 depths. How they find their way is one of those 

 instinctive mysteries often exhibited by insect 

 larvae. These larvce feed on other insect-larvse. 



