DLE DEPT Paes 391 
are well shown in the case of the common house fly. The meta- 
morphoses differ, therefore, considerably in this very natural group. 
There are two great divisions in the order of the Dzftera 
THE METAMORPHOSES OF THE GNAT. 
characterised by distinctions in the antennae; the first section 
have thread-shaped and the second very short antenne, consisting 
of three very distinct joints, and a slender thread which is 
called a style. The first section, the Memocera, have long and 
