MAYER: COLOR AND COLOR-PATTERXS. 187 



spots of different colors fuse, giving a chain of spots which are of 

 one color above and another below. 



In Fig. 16 the spots composing the row BB are blue (dark) 

 above, and red (light) below. It will be observed that the color is 

 bilaterally symmetrical, as usual, about the axis through the middle 

 of the cell. Such bicolored spots are often due to a simple fusion, 

 as before stated ; but sometimes they may, perhaj^s, be intrinsically 

 bicolored. 



Fig. 15 is a beautiful instance of an exception to the general rule 

 that spots are bilateral about the axis through the center of the cell. 

 It is taken from Ornithoptera trojana Staudinger.^ The light spots 

 represented near the outer edge of the wing are of a brilliant irides- 

 cent green. It is evident that they are distinctly bilateral with 

 respect to the nervures ; especialh" is this true of the pair adjacent to 

 nerviu'e 1 . Ornithoptera brookiana Wallace illustrates another 

 exception, though in a less marked degree." Other allied species of 

 Ornithoptera, however, would seem to show that these apjjarent 

 exceptions may have been derived from forms which exhibited two 

 spots in each cell and followed the usual rule. These are the only 

 instances of such exceptions known to me. I do not doubt, how- 

 ever, that further study would reveal others. 



In Fig. 17 an example is given of the peculiar kind of eye-spots 

 found in the Saturnidae. The species from which the figure was 

 taken is Saturnia spini. It will be seen that this so-called eye-spot 

 is quite different in formation from the ocelli of butterflies. It is 

 simply a series of curved cross-bands between nervures, ari*anged 

 symmetrically on both sides of the cross vein CC. The "eye- 

 spots " upon the wings of Attacus hma and in the genus Telea are 

 also of this sort. True eye-spots, however, similar to those found 

 among the Morphos and Satyridae, occur in moths, as in the apex 

 of the fore wing of Samia cecropia, Callosamia promethea, etc. 

 " False " eye-spots are also found on the wings of butterflies ; in 

 Vanessa io, for example, the so-called e3'e-spot of the fore wing has 

 been shown by Dixey ('90) to be made up of a series of fused 

 spots. It will l)e remembered that Merrifield ('94, Plate 9, Fig. 4) 

 caused this '' ocellus " to break up into its constituents by subjecting 

 the pupa to a temperature of 1° C. The ocellus upon the hind wing 

 of Vanessa io is no doubt a true eye-spot ; the only evidence which 



1 See Watkins, '91, Plate 4. 



2 See Hewitson, '5C-'7(!, Vol. 1. 



