COLOR AND COLORATION 2 I I 



lines, a very common style of ornamentation, especially in 

 moths. Or, again, starting with the submarginal shade, this 

 may send shoots or tongues of dark color a short distance 

 toward the base, giving a serrate inner border to the marginal 

 shade; when now this breaks up into one, two, or more lines 

 or narrow stripes, these stripes become zigzag, or the inner 

 ones may be zigzag, while the outer ones are plain a very 

 common phenomenon. 



" A basis such as this is sufficient to account for all the modi- 

 fications of simple transverse markings which adorn the wings 

 of Lepidoptera." 



Briefly, one or more bands may break up into spots or bars, 

 the breaks occurring either between the veins or, more com- 

 monly, at the veins; and in the latter event, short bars. or more 

 or less quadrate or rounded spots arise in the interspaces. 

 From simple round spots there may develop, as Darwin and 

 others have shown, many-colored eye-like spots, or ocelli. 



Mayer gives the following laws of color pattern : " (a) Any 

 spot found upon the wing of a butterfly or moth tends to be 

 bilaterally symmetrical, both as regards form and color; and 

 the axis of symmetry is a line passing through the center of 

 the interspace in which the spot is found, parallel to the longi- 

 tudinal nervures. (b) Spots tend to appear not in one inter- 

 space only, but in homologous places in a row of adjacent 

 interspaces, (c) Bands of color are often made by the fusion 

 of a row of adjacent spots, and, conversely, chains of spots are 

 often formed by the breaking up of bands, (d) When in 

 process of disappearance, bands of color usually shrink away 

 at one end. (e) The ends of a series of spots are more vari- 

 able than the middle, (f) The position of spots situated near 

 the outer edges of the wing is largely controlled by the wing- 

 folds or creases." 



These results- have been arrived at chiefly by the study of 

 the variations presented by color patterns. 



Variation in Coloration. It is safe to say that no two 

 insects are colored exactly alike. Some species, however, are 



