MAYER: COLOR AND COLOR-PATTERNS. 221 



Tables 17 and 19 show the color-variations affecting the "inner 

 j^ellow " and " middle yellow " areas of the fore wing in Heliconius 

 and Eueides. There is but little difference between the two tables, 

 excej^t that in 15 species of Heliconius the inner yellow is suffused 

 Avith black or blue, while the middle yellow is never suffused by the 

 outer black which sm-rounds it. Fig. 100, Plate 10, exhibits 

 graphically the color-variation of these two areas. The "inner 

 yellow" is represented as a full line, and the "middle yellow" as 

 a dotted zig-zag. It is evident that here also the inner yellow is 

 more variable in color than the middle yellow, for not only does the 

 inner yellow area disjjlay two more colors, but its chart is a flatter 

 zig-zag. 



(4) Variations of the " Middle Black " Mark of the Fore Wing. 

 Table 4 shows the color-variation of the middle black mark (area 

 lY in figures uj^on Plate 4) . This marking Ues along the extreme 

 outer border of the central cell of the fore wing. It is small in area, 

 but is rendered very conspicuous from the fact that it is situated be- 

 tween the inner yellow and middle yellow markings. In spite of 

 its small size, however, it is a remarkably permanent marking, for 

 Table 4 shows that it is absent in only 20 out of 400 Danaoid Heli- 

 conidae. In these 20 it has been obliterated by the fusion of the 

 inner and middle yellow areas. It is worthy of note that in 12 

 Ithomias it has become rufous in color. This change to rufous is 

 the only color-change which the black areas of the wings ever 

 display. 



Table 18 shows the variations of the middle black area for 

 Heliconius and Eueides. 



(5) Variations of the '•'■ Outer Yelloxo'''' Area of the Fore Wing. 

 Table 6 shows the variations which affect the outer yellow area 

 of the fore wings in the Danaoid Heliconidae. This area is marked 

 VI in the figures upon Plate 4 ; it lies beyond the region of the 

 middle j-ellow, but is usually more or less fused with it. Table 6 is 

 onh'- approximately correct, owing to the difiiculty in many cases of 

 deciding whether the middle and outer yellow be really fused or not. 

 It will be seen that in the genus Ithomia the middle and outer 

 yellows are wholly fused in about 200 species. This is one of the 

 marked characteristics of this verj' independent genus. 



Table 20 shows the color-variations of the outer yellow area in 

 Heliconius and Eueides. This marking is present in 81 and absent 

 in 48 of the Acraeoid group. It is much more widely separated 

 from the middle yellow than is the case in the Danaoid group. 



