128 FLIES. 



If one notes carefully this dainty bit of wing 

 structure, he will be well repaid for his trouble, 

 by seeing the beautiful, ingenious contrivances 

 which strengthen and sustain the gauze-like tex- 

 ture of the wings and render them suitable for the 

 performance of flight. Here is a wonderful sys- 

 tem of venation ; a framework with all its pieces 

 nicely joined together, like the whalebone ribs of 

 an umbrella. From the four main trunks, at the 

 base of the wings, branch out six supporting limbs, 

 at different angles and with various curves, length- 

 wise over the soft, almost transparent surface. 

 These are called longitudinal veins, and are con- 

 nected by large and small cross-veins at different 

 places. These supporting ribs are stouter and 

 more rigid along the front part of the wing than 

 those on the posterior part. 



One is fascinated in examining the manifold 

 patterns and diagrams that Nature has drawn on 

 the wings of flies ! It is by studying the various 

 designs, that the many families and genera are 

 identified. How many species there are to be 

 interested in, that never visit the houses, except 

 as stragglers ! Their haunts are in the deep 

 woods, along streams and ponds, in sedgy swamps, 

 grassy fields and wild-flower patches, and it is to 

 these localities one must go, if he would study 

 their actions and curious life histories. 



If one walks across the fields in April or May 



