254 ANNULATA. 
The ‘Cabbage White” lays its eggs on cabbages and 
turnips which the larvee devour. A great number of the 
night-flying moths have underground caterpillars which do 
damage to crops. 
The relationship of Zefidoptera to flowers and the cor- 
related structural modifications in each are full of interest. 
In a general way, the flowers employ Lepidoptera to carry 
pollen, and so fertilise and attract them by a supply of 
nectar. 
ORDER V.—LVeuroptera. 
Fig. 175.—DEMOISELLE DRAGON FLy 
(Agrion puella ). 
Notice the Nervured Wings. 
The Weuroptera have biting mouth parts and two pairs 
of membranous wings, usually of equal size and covered 
with a network of veins. The metamorphosis is usually 
incomplete, but in many cases is complete. 
The most important of the Meuroptera are the Dragon- 
flies, with an incomplete metamorphosis and an aquatic 
larva with a movable labium like a hand; the May-flies, 
also with aquatic larvee, the fly only living a few hours; the 
Caddis-flies, the aquatic larvee of which protect themselves 
in cases of twigs or stones and pass through a complete 
metamorphosis with a pupal stage; lastly, the Ant-lions, the 
larval stage of which digs traps for ants. 
