140 



REPORT OF STATE GEOLOGIST. 



The second group, the H eterometabola, comprises those insects in 

 which the metamorphosis is incomplete; the young, when hatched 

 from the egg being wholly wingless and of the same general form as 

 the parent. As the insect grows it moults its skin a number of times 

 and wings develop gradually, there being no sharp line defining the 



Fig. 14. Partial metamorphosis of Jtfe^awopius/emt/r-ruftrum, showing the five nymph stages 



and the partial growth of the wings, which are first visible externally in 3,3b, 3c. 



(After Packard.) 



