i MIMICRY IN THE COLORS OF INSECTS. 393 
The patterns on the wings and elytra could not be the product 
of the action of muscles, but I believe it to be probable that the 
sudden rush of blood or even air, by the accelerated circulation and 
respiration in the act of transformation may have the same effect. 
In this way some patterns, otherwise not explicable, could be under- 
stood. The eyespots in the caterpillars of some Papilionide have 
been ascertained by Leydig to be epidermal colors, and I believe 
that the various kinds of eyespots in the wings of the imago are also 
epidermal colors. If a stream of blood meets a small obstacle 
just in the centre, a funnel is formed; if this obstacle is a ring, 
and behind it another obstacle we have two or more funnels, one 
in the other, and the section of them will be circular or elliptical 
according to the angle at which they reach the surfaces. Such 
patterns in the elytra and wings are formed or preformed at the 
time when the wing is a sac ; sometimes before the transformation, 
and here is another circumstance which explains some patterns. 
The walls of the sac are suddenly augmented and strongly dilated 
in the transformation. Small patterns preformed in the sac will 
also be altered and enlarged by the same process, and I know that 
many patterns of Lepidopterous wings are in such a way very 
easily explained. All the waved lines of the wings and other 
marks belong here, and as the ribs or nervures seem to grow 
faster in transformation, the waved appearance would be explained. 
In fact the greater part of the patterns seem to be produced by 
expansions or distraction of the pattern preformed in the wing at 
Some period before the transformation. 
re NSOE EA NEA 
on the vine by their color re numerous than would be suspected. 
vag mistakes in the color of green and red light by officers of the signal 
He gives the statement that usually one in twenty, and in the soldiers exam- 
fty was subjected to color-blindness. But these numbers show only the 
eater num r less aff 
In fact we have no means of measuring this physiological difference ; if two 
there is no cama , and even compare the color with certain known objects 
dent in © proof at all that they see just the same color. I think that it would be pru- 
describing cases of mimicry, especially when they are extraordinary, not to 
Sirsa, even the best observer may be unaware of this infirmity, and in fact the 
horities on color-blindness always state that the greater number of persons 
i ity, 
Mare no idea of their infirmity 
