oO 



DAMSEL PLY (at the left) 



DRAGON FLY (in the center) 



XYMPTH OF DRAGON FLY 



Flies and dragon-flies have most wonderful eyes, — huge 

 convex, compound eyes containing upwards of twenty 

 thousand simple eyes. Each of these eyes sees bv itself, 

 taking in very narrow rays of liglit, but the whole aggrega- 



