MAYER: COLOR AND COLOR-PATTERNS. 225 



There is, apparently, but one important respect in which the 

 Danaoid HeHconidae are more variable than the PapiUos, and that 

 is size. For example, Lycorea ceres, which is probabh^ the largest 

 of the Danaoid group, has 2,2 times the spread of wing of Ithomia 

 nise, which is one of the smallest (see Plate 4, Figs. 46 and 54). 

 The largest Paj^iUo, P. androgea, on the other hand, spreads only 

 2.16 times as much as the smallest, P. triopas. 



There is another minor respect in which the color-patterns of the 

 Papilios are different from those of the Heliconidae. In the HeH- 

 conidae the fore wing slightly overlaj^s the hind wing, and that por- 

 tion of the hind wing which is hidden from view is always dull in 

 color (see Plates 5-8) . In the Papilios, however, the fore wing 

 does not overlap the hind wing to such an extent as in the Helico- 

 nidae, and it is worthy of note that the costal edges of the hind 

 wings in the PapiUos are as brilliantly colored as are any other por- 

 tions of the wings. 



It is difficult to account for the remarkable conservatism in respect 

 to color-variations among the Heliconidae, unless we resort to the 

 explanation afforded by the theory of mimicry ; for, while there is 

 such remarkable simplicity and uniformity of color-pattern through- 

 out the whole group of the Heliconidae, individxial variations 

 are very common. In the collection at the Museum of Compara- 

 tive Zoology, for example, one finds a regularly graded series of 

 specimens of Heliconius eucrate ; at one end of this series the 

 "inner rufous" area of the hind Aving is bright yellow, and at 

 the other end it is rufous ; intermediate specimens are found in 

 which this area is yellow, but dusted over with rirfous scales. Also 

 the " middle black band " of the hind wings in Melinaea parallelis 

 is very variable, some specimens showing it broken in the middle 

 (Plate 7, Fig. 82), and others having it as an entire baud. I have 

 also seen one specimen of H. burneyi in which the commonly 

 yellow spots upon the under surface of the wings were changed to 

 white. Another good instance of individual variability is afforded 

 by H. phj'lhs (Plate 5, Fig. 65), for in this species the series of 

 small red spots sometimes found just below the yellow band upon 

 the hind wing is very variable, and more often absent than present. 

 Still other instances of individual variability are seen in the yellow 

 stripes upon the wings of H. charitonius (Plate 5, Fig. 64), which 

 are often found tinged with rufous. Also the remarkable diversity 

 in Mechanitis polymnia, and M. isthraia (Plate 7, Figs. 84-87) are 



