EVOLUTION OF COLOR PATTERN IN LITHOCOLLETIS. 129 
A specimen at a somewhat later stage (Fig. 13) shows a little more of the 
orange brown tint, but the color is nowhere as deep as in the adult. The formerly 
colorless area in the middle of the wing is still distinctly set apart from the rest 
of the wing but has become narrower and is beginning to acquire a faintly vel- 
lowish tinge. The white’ streaks are now definitely blocked out due to the 
curving in of the yellow color; they are, however, still connected with the whitish 
middle portion of the wing. The patch of blackish scales near the apex has 
increased in extent and depth of color until its identity with the patch of black 
scales in the apex of the adult wing is clearly established. It has now reached 
its adult condition, and no further change takes place. rum т үү, 
The early origin and differentiation of this patch of uU e _. 
scales shows clearly that it is a character quite sepa- ex zx 
rate and distinct from the dark line of scales in the | ч 
adult extending from it toward the base of the wing. Fic. 13. Later stage in the 
The scales around the apex, yellow in the earlier stages, ancy amma NE 
are now tipped with pale brown, but the outermost row 
of scales are still whitish as before. There is some deepening of the ground 
color just before the first and second pairs of streaks; the second dorsal streak, 
however, is the only streak which can be said to have acquired a definite mar- 
gin, and even this is pale brownish. The basal streak remains entirely un- 
margined. 
In a specimen at a little later stage than that just described, internal margins, 
though very pale, have appeared along all of the white streaks; that of the second 
dorsal still continues to be in advance of the others. The margin of the first 
costal streak has deepened somewhat, and there is a faint suggestion of gray 
around its tip. A similar pale gray shade extends from the tip of the first dorsal 
streak through the middle of the wing and around the tip of the second dorsal 
streak. The ground color along the upper edge of the basal streak is somewhat 
darkened, but there is no margin. 
In a wing at a considerably later period of development, the ground color 
approaches the adult color over those areas where there are no brown scales. 
The internal margins of the costal and dorsal streaks, as well as the upper margin 
of the basal streak, are dark brown; the external margins of these streaks and 
the margin around the tip of the basal streak while present are not as dark as 
in the adult and show a decidedly grayish tinge. This same gray color is pro- 
longed from the tip of the first dorsal streak along the middle of the wing in the 
area formerly colorless but is much paler than in the adult. This difference from 
the adult color is especially noticeable above the patch of black scales, where 
in the imago there is a decided deepening of color, almost blending with the 
black patch. There is but very little deepening of color between the first and 
second dorsal streaks, and the margin of the second dorsal streak is neither as 
deep nor as wide as in the adult. The darkening of scales in the cilia started in 
earlier stages still continues. There is, however, no change from the colorless 
condition of the scales which are to be deep iridescent blue. 
