OF ORNAMENTA TION. 211 



shall presently mention. It would, therefore, 

 seem not unlikely that we shall be forced to dis- 

 card the idea of direct physical causation in the 

 one case as in the other. This thesis, however, it 

 is not my purpose here to maintain. I merely 

 wish to draw attention to the point before pro- 

 ceeding to discuss the origin and development of 

 ornamentation in butterflies. 



I have seen only a single attempt to trace the 

 origin of the color-patterns of butterflies by the 

 light of modern ideas. This was the subject of a 

 short article by Rev. Mr. Higgins, published 

 some years ago in the Quarterly Journal of 

 Science. This writer maintains that what he 

 terms the primary or fundamental pattern was a 

 " pale ground with darker linear markings fol- 

 lowing the course of the veins ;" and he explains 

 its origin from the earliest monochromatic wing, 

 by supposing that " the scales growing on the 

 membrane upon or near the veins would be dis- 

 tinguished from the scales growing on other parts 

 of the membrane by a freer development of pig- 

 mentary matter" within them. From this simple 

 form of linear markings he would derive all those 

 patterns which bear definite relations to the veins, 

 such as the dark bands which cross them at an 

 angle and are scalloped between each pair ; thus 

 he says : " a portion of the dark scales begin to 

 diverge on each side from the veins," and " the 



