10 



ANIMAL BIOLOGY 



the unaided eye this colored substance from the wing ap- 

 pears to have no definite form; in fact, it looks like the 

 pollen from flowers. An examination with the compound 

 microscope, however, shows that each 

 of these tiny bodies has a definite 

 shape (Fig. 7). Each scale has at 

 one end a tiny stem, but in other re- 

 spects they vary considerably in form. 



The scales are attached in the follow- 

 ing manner. In the membrane of the 

 wing are openings into which fit the 

 stems of the scales. The latter are 



FIG. 7. Scales from arranged in rows and overlap some- 

 wing of a butterfly. ,, . ,., ,, , . , ,, 



thing like the shingles on a roof 



(Fig. 8) . In spite of this arrangement it is evident that the 

 scales are not firmly attached, since the slightest touch is 

 sufficient to dislodge many of them. Rough handling was 

 not apparently planned for in the con- 

 struction of these insects. The pres- 

 ence of these scales on the wings of 

 butterflies and of their near relatives, 

 the moths, is so characteristic that 

 these insects have been called the 

 Lepidoptera (Greek, lepido = scale + 

 ptera = wings). Not only are scales 

 found on the wings but, in the shape 

 of hairs, they form a fuzzy growth 

 over the surface of the whole body. scales. (Coleman.) 



9. Proboscis. Another marked characteristic of butter- 

 flies and moths is the sucking tube, or proboscis. While the 

 proboscis seems to be a single structure, in reality it is com- 

 posed of two slender appendages, each having a groove on 



