392 MIMICRY IN THE COLORS OF INSECTS. 
Moreover a certain and constant pattern can be found for the 
head, a different pattern for the segments of the thorax, and a 
different pattern for the segments of the abdomen. This pattern 
is in the different segments of the abdomen (Hymenoptera, Diptera, 
Neuroptera, Orthoptera) always the same, only more or less 
elaborated, and less finished in the first and last segments. In 
some way the same is true for the thoracic segments. 
In some few instances I was able to observe how the pattern is 
produced. In the Odonata (Dragon flies) at the moment of trans- 
formation the thorax is transparent, and shows no colors at all. 
At this time the muscles are without importance and in process 
of formation. The thoracic muscles as is well known are, in the 
Odonata, very powerful, and also very extraordinary as regards 
the shape of their tendons. Just along outside the muscles are 
dark lines more or less well finished, and resulting from the action 
of the muscles. Ubi irritatio, ibi affluaus. 1 believe that it would 
not be unphilosophical to conelude that a powerful action in the 
development of the muscles is in such a case the cause of a greater 
combustion or oxidation in the neighboring parts. In fact on 
the head of a Cicada, on the abdomen of an Æschna we find 
similar patterns, in some way mostly representing the underlying 
muscles. In the Gomphina the fact is striking and far more as 
the stronger species mostly possess a larger dark pattern. 
are some very small species which are almost entirely 
there are no small species entirely black. 
Should the fact, with the explanation, be admitted, a step far- 
ther in the explanation of the different patterns would be made. 
I know very well that in the Odonata there are patterns which do 
not agree with my explanations, even some contrary to it, but 
if some certain facts be explained, there are perhaps more factors 
still unknown or unobserved. The explanation given for ocn” 
facts would still be admissible, or at least not entirely objection’ 
ble.* 
There 
yellow ; 
s far as 1 know the literature relating to the phenomena of mimicry, a 
related differences are often confused, and I believe that in separating pagea 
lowing the views above given, many facts would be better understood and j ‘ 
ing subject more easily advanced. ‘ -o is one more ; 
Besides all the difficulties which oppose a clear and correct view, anne different : 
which I do not find mentioned, i. e. the so called color-blindness exp “ nthrop® 
Chapter. Persons who cannot distinguish ripe cherries upon 
