240 



zoClogy 



spicuous. The underwing moth is 

 another example of a wonderful sim- 

 ulation of the background of bark 

 on which the animal rests in the 

 daytime. At night the brightly col- 

 ored under wings probably give a 

 signal to others of the same species. 

 The beautiful luna moth, in color a 

 delicate green, rests by day among 

 the leaves of the hickor}^ The small 

 measuring worms stand out stiff upon 

 the branches on which they crawl, 

 thus simulating lateral twigs. Hun- 

 dreds of other examples might be 

 given. 



This likeness of an animal to its 

 immediate surroundings has already 

 been noted as ^protective resemblance. 



Reference Books 



The underwing moth; above, flying; p^j^ ^jj^, PUPIL, 



below, at rest on bark. 



Burnet, »Sc/20oZ ZooZogr?/, pages 101-111. American Book Company. 



Davison, Practical Zoology, pages 68-91. American Book Company. 



Herrick, Text-book in General Zoology, Chap. XV. American Book Company. 



FOR THE TEACHER 



Dodge, General Zoology, pages 113-118. American Book Company. 



Dickerson, Moths and Butterflies. Ginn and Company. 



Sanderson, Insects Injurious to Staple Crops. John Wiley and Sons. 



The J'lies 



The House Fly} — Examine a house fly, find the divisions of the body. 

 Notice the small hairs covering parts of it. The wings appear to be only 

 two in number — hence the name Diptera. Behind the gauzy wings you 

 will find the second pair of wings have developed as knobbed hairs, called 

 the balancers. They seem to have the double function of giving aid in 

 balancing and in hearing. 



Notice the shape of the head. Is it freely movable? The antennae are 

 very short, while the eyes are enormously developed. Test with moving 



* See Hunter and Valentine, Mamud, page 114. 



