The wings of insects are mostly covered with hairs or scales, several examples of which are given in Plate VIII. Fig. 4 shows one of the scales of the Adippe or fritillary butterfly, exhibiting the double membrane--part of which has been torn away--and the beautiful lines of dots with which it is marked. The structure of the scales is further shown by a torn specimen of tiger moth scale seen on Fig. 16. On many scales these dots assume a “watered” aspect when the focus or illumination changes, an example of which may be seen in Fig. 15, a scale of the peacock butterfly. Fig. 11 is one of the ordinary scales of the azure blue butterfly, and Fig. 10 shows one of the curious “battledore” scales of the same insect, with its rows of distinct dottings. Fig. 14 is one of the prettily tufted scales of the orange-tip butterfly, and Fig. 8 is the splendid branched scale of the death’s-head moth. Fig. 19 shows a scale of the sugar-runner (_Lepisma saccharína_), a little silvery creature with glistening skin, and long bristles at the head and tail, that is found running about cupboards, window-sills, and similar places. It is not easy to catch with the fingers, as it slips through them like oil; but by holding a cover-glass in a pair of forceps, and pressing it upon one of the little creatures, a number of the scales may be caused to adhere to it, and these should be mounted dry for examination. The gnats also possess very pretty scales, with the ribs projecting beyond the membrane. VII. FIG. 1. Tongue, Hive Bee 2. Do. Tortoiseshell Butterfly 3. Do. do. one of the barrel-shaped bodies 4. Head, Violet Ground Beetle (Carabus) 5. Tongue, Cricket 6. Do. do. 7. Head, Scorpion Fly (Panorpa) 8. Leg, Ant 9. Proleg, Caterpillar 10. Do. do. single hook 11. Proboscis, Fly 12. Do. do. “modified trachea” 13. Part of Foreleg of Water Beetle (Acilius) 14. Do. large sucker 15. Leg, long-legged Spider (Phalangium) 16. Do. Harvest-bug (Trombidium) 17. Do. Glow-worm 18. Do. Dung fly 19. Do. Asilus 20. Do. Acarus of Dor-beetle 21. Claws and Pad, Ophion 22. Wings, Humble Bee 23. Do. 24. Wing hooks, hind wing of Aphis 25. Wing hooks, Humble Bee 26. Foot, Flea 27. Stomach and gastric teeth, Bee 28. Three teeth of do. 29. Cast skin, Larva of Tortoise Beetle (Cassida) 30. Balancer, Blow fly 31. Wing, Midge (Psychoda) 32. Do. do. part of a nervure with scales 33. Stomach and gastric teeth, Grasshopper 34. Spiracle, Wire-worm [Illustration: VII.]