Spots and Stripes. 45 



in our possession. In the males of both Levana, Fig. 4, and 

 prorsa, Fig. 1, the hind-wing has a distinct row of spots, and a 

 less distinct one inside it, and in the females of both these are 

 represented by dark stripes. In poritna we get every intermediate 

 form of spots and stripes, both in the male and female, and as these 

 were hatched from the same batch of eggs, or, are brothers and 

 sisters, it is quite impossible to doubt that here, at least, we have an 

 actual proof of the change of spots into stripes. 



The change of spots more or less irregular into eye-spots, or 

 ocelli, is equally clear ; and Darwin's drawing of the wings of Cyllo 

 leda* illustrates the point well. " In some specimens," he remarks, 

 " large spaces on the upper surfaces of the wings are coloured black, 

 and include irregular white marks ; and from this state a complete 

 gradation can be traced into a tolerably perfect ocellus, and this 

 results from the contraction of the irregular blotches of colour. In 

 another series of specimens a gradation can be followed from 

 excessively minute white dots, surrounded by a scarcely visible 

 black line, into perfectly symmetrical and larger ocelli." In the 

 words we have put in italics Darwin seems to admit these ocelli to be 

 formed from blotches ; and we think those of the Argus pheasant can 

 be equally shown to arise from spots. 



Darwin's beautiful drawings show, almost as well as if made for 

 the purpose, that the bars are developed from spots.f In Fig. 1 is 

 shown part of a secondary wing feather, in which the lines k. k, 

 mark the direction of the axis, along which the spots ar& 

 arranged, perfectly on the right, less so on the left. The lengthen- 

 ing out of the spots towards the shaft is well seen on the right, and 

 the coalescence into lines on the left. In Fig. 2 we have part oi 

 another feather from the same bird, showing on the left elongated 

 spots, with a dark shading round them, and on the right double 

 spots, like twin stars, with one atmosphere around them. Increase 

 the elongation of these latter, and you have the former, and both 

 are nascent ocelli. We here, then, have a regular gradation 

 between spots, bands, and ocelli, just as we can see in insects. 



In some larvae, those of the Sphingidce especially, ocelli occur, and 

 these may be actually watched as they grow from dots to perfect 

 eye-spots, with the maturity of the larva. 



Even in some mammals the change from spots to stripes can be 



* Desc. Man, vol. ii., p. 133, fig. 52. 

 t Compare his figs. 56 to 58 op. cit. 



