150 



HINTS ON THE ANCESTRY OF INSECTS. 



represents the larva (Leptus) of the red garden mites ; while a 

 figure of the "water bear," or Tardigrade (Fig. 183), is intro- 

 duced to compare with it, as it bears a resemblance to the 

 young of the mites, though their young are born 

 with their full complement of legs, an exception 

 to their nearest allies, the true mites. Now if 

 we compare these early stages of mites and 

 myriopods with those of the true six- footed 

 insects, as in the larval Meloe, Cicada, Thrips 

 and Dragon fly, we shall see quite plainly that 

 they all share a common form. What does this '' ^ 



mean ? To the systematist who concerns him- ^^^- ^^^P*"^- 

 self with the classiflcation of the myriads of different insects 

 now living, it is a relief to find that all can be reduced to the 

 comparatively simple forms sketched 

 above. It is to him a proof of the 

 unity of organization pervading the 

 world of insects. He sees how nature, 

 seizing upon this archetypal form has, 

 by simple modifications of parts here 

 and there, by the addition of wings and 

 other organs wanting in these simple 

 creatures, rung numberless changes 

 in this elemental form. And starting 

 from the simplest kinds, such as the 

 Poduras, Spiders, Grasshoppers and 

 May flies, allied creatures which we 

 now know were the flrst to apuf ar in 

 the earlier geologic ages, we rise to 

 the highest, the bees with their com- 

 plex forms, their diversified economy 

 and wonderful instincts. In ascending 

 this scale of being, while there is a 

 progress upwards, the beetles, for in- 

 stance, being higher than the bugs and 

 butterflies and moths, on the whole, 

 being more highly organized than the flies; and while we see the 

 hymcnopterous saw-flies, with their larviB mimicking so closely 

 the caterpillars of the butterflies, in the progress from the saw- 

 flies up to the bees we behold a gradual loss of the lower 

 saw-fly characters ia the Cynips and Chalcid flies, and see in 



183. Tarrligrade. 

 grasshoppers; and the 



