FROM THE EGG 127 



grow after they attain the imago or "perfect 

 insect" condition. A small fly will never be- 

 come a large fly, nor a small beetle a large 

 beetle. This is only because we do not recognize 

 their caterpillars or grubs as flies and beetles ; 

 but a grasshopper we know grows, because its 

 early stages are of the same general form as the 

 perfect insect, and we see the little ones hopping 

 about in some places, and if we visit the same 

 place later on we notice that they have grown, 

 but as soon as they cast their last skin and obtain 

 the free use of their wings, growth ceases, as it 

 does in a fly or a beetle or in any other 

 insect. 



It must not be supposed that the limbs of insects 

 are of no value in their identification. We only 

 removed them in order to emphasize the great 

 importance of the character derived from the 

 regional constrictions of the body, which is 

 considered to be certainly one of the most, if not 

 the most, important of any. Besides this char- 

 acter every perfect insect should have six legs, 

 four wings, and various appendages on the head? 

 such as antennae, mandibles, maxillae, labium, etc.; 

 some of these may be so modified as hardly to 



