268 ANIMAL SKETCHES. CHAP. 



question now arises, is it one structure or many ? Is it 

 an eye, or an aggregate of eyes ? 



To this question the older naturalists answered con- 

 fidently an aggregate. And a simple experiment seems 

 to warrant this conclusion. Puget, quoted in Gold- 

 smith's Animated Nature, adapted the facets of the eye 

 of an insect cleaning away the soft parts behind the 



EYE OF FLY. 

 Transverse section through head. (After Hickson.) 



cornea and its lenses so as to see objects through it 

 under the microscope. "-A soldier who was thus seen, 

 appeared like an army of pigmies; for while it multi- 

 plied, it also diminished the object ; the a,rch of a bridge 

 exhibited a spectacle more magnificent than human skill 

 could perform ; and the flame of a candle seemed the illu- 

 mination of thousands of lamps." Although Mr. Cheshire, 

 in his book on the bee, adopts this view and supports it 

 by reference to a similar experiment, it numbers to-day 



