196 THE REIGN OF LAW. 



insects. And this, which is perhaps the subordi- 

 nate purpose in the case of the Mqntidce, emerges 

 as the main purpose in another family of imitative 

 insects, the PJiasmidce. These last are vegetable 

 feeders, and their imitative structure is, if possible, 

 even more wonderful, as it certainly is more beau- 

 tiful. In some species the wings are not only 

 made like leaves in form, in structure, and in 

 general colour, but they are tinted at different 

 seasons of the year with the varying colours of 

 spring, of summer, or of autumn. The fundamental 

 green is shaded off into browns, and reds, and 

 yellows, with a few of those crimson touches which 

 are so common in the " Pageant of the year." 

 There is one specimen in the British Museum 

 where the imitative effect is pursued, as it were, 

 into a region of still more minute and curious 

 observation. The general aspect of summer vege- 

 tation is much affected by the ravages of insect 

 life. Minute larvae eat into the cuticle of leaves, 

 and mark them with various spots of bleached or 

 faded colour. Now the specimen of PJiasma I 

 refer to has its wing covered with spots which 

 exactly imitate this appearance of a larva-eaten 



