MAYER: COLOR AND COLOR-PATTERNS. 
253 
lack of pigment, which is developed later. If one treats the scales at 
this stage with oil of cedar-wood or clove oil, they become practically 
invisible under the microscope, thus demonstrating that there is 
no pigment within them. Fig. 26, Plate 3 , gives the appearance 
presented by a scale taken from the light drab-colored margin of 
the mature wing. This is about the lightest area upon the wing 7 
except the white spots ; but it will be seen that this scale is much 
darker in appearance than the unpigmented one shown in Fig. 25. 
The white or unpigmented condition of the wing lasts for about 
four days. The wings then become uniformly tinged with an 
impure yellow or light drab, and very soon after this the colors 
begin to make their appearance. They first appear upon the lower 
surface of the wings. Fig. 28, Plate 3 , represents the under 
surface of the fore wing of a female in a very early stage of color 
development; in fact the upper surface shows, as yet, no trace of 
the colors. It will be seen that a few dark red streaks have 
appeared near the central portion of the wing, and it is worthy of 
note that these occupy the interspaces between the nervures. The 
ocellus near the apex of the wing appears faintly outlined upon its 
background of impure yellow. 
Fig. 27, Plate 3 , represents the under side of a hind wing of 
a male in about the same stage as Fig. 28. Here, again, the red color 
occupies the interspaces , and indeed it is only later that the nervures 
become clouded over by it. 
Figs. 29 and 30, Plate 3 , represent, respectively, the under and 
upper sides of the fore wing of a male about five hours after the 
first appearance of the colors. Upon the upper side (Fig. 30) we 
see two gray streaks near the base of the wing and a light cinnamon- 
brown color extending from the lower edge toward the middle of 
the wing. The ocellus near the apex is now quite apparent, but 
still faint in color. On the under surface (Fig. 29) the red markings 
have developed to a much greater extent than in Fig. 28. The 
outermost of the two white spots which occupy the center of this red 
area becomes the white central spot of the mature wing; the inner¬ 
most one is soon obliterated owing to its becoming clouded over 
with red. 
Figs. 37 and 36 represent respectively the upper surface of 
the fore wing and the lower surface of the hind wing of a female, 
slightly more advanced than in Fig. 30. Fig. 31 represents a male 
and Fig. 38 a female about twelve hours after the first appearance 
