57 



ing the group to which this larva bclon2;s, leave the'water while they are still in the larval state 

 and do not usually become pupse for several days or even weeks thereafter. Hence the Creator 



Fig. 47. 



Colours — (a) rk bro\vn, (h) wliitish, (r) aiul ((/) light brown. 



to meet their necessities has given them a double system of respiration— a set of gills to 

 breathe with in the water, and a set of breathing holes, or spiracles, to breathe with upon 



Fig. 4S. 



