DESCRIPTION OF PLATES. XIX 



FIG. PAGE 



208. Head of common spider, showing eight simple eyes. 



a. Cornea of one of these more magnified. ...... 85 



209. Skin of garden spider 85 



210. Portion of compound eye of fly 83 



211. Portions of the two wings of bee in flight 88 



a. Nervule of wing. 



212. Spiracle of fly 86 



213. Spiracle of Dytiscus 86 



214. Threads of garden spider {Epeira diadema) 86 



Simple thread of the same. 



Thread of a concentric circle with viscous dots. 



PLATE VIII. to face page 83. 



215. Fore leg of Gyrinus natator, whirligig beetle . . , , 87 



216. Middle leg of the same 87 



217. Hind leg of same 87 



218. Fore leg of male Dytiscus 87 



219. Middle leg of the same. 



220. a. Gizzard of cockroach 89 



6. Ditto, cut open. 



221. a. Gizzard of cricket 89 



h. Ditto, cut open. 



222. Trachea from caterpillar 86 



223. Proleg of caterpillar of common garden white 



butterfly, with the membranes in which the 



hooks are seated, expanded as in action 88 



224. Part of leg of cockroach 



225. Battledore scale from blue argus butterfly 88 



226. Scale of ordinary shape from same 88 



227. Scale from meadow-brown butterfly 88 



228. Scale of gnat 83 



