MIMICRY IN THE COLORS OF INSECTS. 391 
females of the same species, the epidermal colors rarely differ so 
far as I know; but there are genera with prominent epidermal 
colors which are nearly always different in different sexes, viz, 
Calopteryx, Lestes, some Hymenoptera, ete. 
It would be interesting to know the different colors of the epider- 
mis in such cases. So far as I know the change seems to be 
between related and not between complementary colors. But my 
observations are far from having any conclusive importance. The 
same investigation would be. necessary for the hypodermal colors. 
The hypodermal colors may change or be altered in some way 
in a male or female during its lifetime, by sexual or other influ- 
ences. The epidermal colors never change. By sexual influences 
yellow is changed into orange, brown into red, and even sometimes 
more changed. By other influences, for instance by cold in 
hibernation, pale yellow is changed into red (Chrysopa). The 
‘Aypodermal colors can be changed even by a voluntary act of the 
animal, and the new colors disappear again (Cassida). The 
hypodermal colors are the only ones on which the animal has any 
influence either involuntarily by the action of the nutritive fluid or 
Voluntarily. The epidermal cells are placed entirely outside of 
any influences of the animal, when once established. It will per- 
Perhaps be possible to prove that the so-called mimetic colors are 
all hypodermal colors. es 
The hypodermal colors seem to be produced by a photographic 
erpcene (I know no better expression), the epidermal colors by a 
chemical process of combustion or oxidation. Would it be possi- 
ble to prove that by a photographic process even the colors of 
the surrounding world could be transmitted, a great step towards 
an undertaking of the phenomena would be given. The fact of 
Course is very probable, at least in some instances. 
In observing the mimicry, the pattern of an insect must be 
= “UJ Separated from the color. In fact the pattern is not the 
_ Product of an accidental circumstance, but apparently the product 
A certain law, or rather the consequence of certain actions or 
: eels in the interiur of the animal and in its development. The 
: a 'S very easily afforded by the regularity of the pattern in 
ace sia or a family of insects. If studied carefully and compara- 
G y the pattern in a genus is the same or is only more or less 
=" The number of such families is so exceedingly great 
— Some example will readily occur to every one. 
