OF ORNAMENTATION. 215 



in the differentiation of the primordial uniform 

 coloring. 



To carry this theory another step : By the 

 breaking up of any one or more of these bands 

 into spots or bars, we may conceive two new 

 forms of pattern according as the break occurs in 

 the interspaces or at the veins. In the former 

 case, the tendency of dark scales to cluster along 

 interruptions of any nature in the surface, 

 whether veins, folds, creases, or margins, to- 

 gether with the concentrating force presumed in 

 a rupture of the band, will be sure to cause the 

 scales to collect along the veins, and, uniting 

 with similar spots upon them, to border the vein 

 on either side continuously. This will map the 

 veins very distinctly upon the ground, producing 

 in fact that condition of things which Mr. Higgins 

 considers the primary pattern, but which, cer- 

 tainly, we rarely find in moths and not very com- 

 monly in the highest butterflies. Indeed, when 

 carried to an extreme, as in the dark- veined in- 

 sects with otherwise diaphanous wings, we find it 

 only in some of the very highest moths (Aegerians 

 and Sesiadae) or butterflies (Heliconians). The 

 junction of these darkened veins with the darkened 

 border of the wings produces, I suppose, the 

 series of spots upon the tips of the veins which 

 sometimes occur there, but, as already stated, on 

 no other part of the veins. 



