COLORS AND MARKINGS OF ANIMALS 



439 



wings of butterflies and moths, we can very advantageously 

 use these beautiful insects in beginning the study of animal 

 colors. 



The scales and colors of butterflies' wings. Catch a 

 few butterflies of different kinds and kill in the killing-bottle. 

 With the finger rub lightly one of the wings and note that a 

 fine dust-like substance comes off on the finger-tip, and 

 that at the same time the pattern and color disappear. By 

 gentle steady rubbing with thumb and finger just opposite 

 each other on the upper and lower sides of the wings, a 

 clear, transparent spot may be made. It is evident that 

 the color and pattern of the wing depends upon its covering 

 of fine particles. 



a 



FIG. 225. Single scales from moths and butterflies; a, from Tolype velleda; 

 b, from Castnia sp., c, from Micropteryx aruncella. (Greatly magni- 

 fied.) 



Rub some of this color-dust from the finger-tip on a 

 glass slide and examine under the microscope. Note that 

 the fine particles are all scale-like in shape and character, 

 each being composed of a tiny short stem and a broader 

 flattened blade which may have the margin of its broad 

 free end even or dentate, that is, showing little teeth or 

 fingers (fig. 225). These tiny scales are hollow, and inside 

 they may contain only air, in which case they are transparent 

 or whitish under the microscope, or they may hold small 

 granules of pigment, a colored substance which makes 

 them brown or yellowish or reddish or blackish, 



