A Study of the Biology of Saturniid Moths 
in the Canal Zone Biological Area 
By A. D. BLEsT 
Department of Zoology, University College, London 
[With 5 plates] 
Current evolutionary biology has seen a striking revival of interest 
in the theory of protective coloration. The essence of the several 
separate hypotheses of which the theory is composed is that all, or 
nearly all, animal coloration is meaningful in that it confers pro- 
tective advantages upon the animals bearing it, and that the various 
categories of special adaptations, such as procrypsis, the mimicking 
of palatable forms by those which are distasteful, and the advertise- 
ment of distasteful forms by bright and contrasting color, have all 
been evolved in response to selection pressures mediated by predators. 
The earlier widespread interest in protective adaptations, which was 
largely fostered by Sir Edward Poulton and his school in Oxford at 
the end of the 19th century, did not survive in its full vigor to ex- 
perience the discipline which 20th-century genetic analysis could have 
imposed upon its largely anecdotal framework. Instead, in the period 
between the wars, it withered under the critical fire of laboratory 
zoologists who were unable to accept the apparent gap between the 
abilities which protective adaptations seemed to demand of the preda- 
tors against which they had supposedly been evolved, and the abilities 
which such animals were known, as scientific fact, to possess. 
To a great extent, this skepticism followed from an experimental 
discipline of behavioral research which placed too much emphasis 
upon the simpler reflex and tropistic phenomena. Then, too, nat- 
ural selection had replaced God in the problem of creation; and its 
creators, losing faith in their demon, were now unwilling to admit 
that it was a fine enough instrument to achieve those ends which were 
manifestly present in nature as fatts accomplis. On the one hand, in 
the shape of butterflies perfectly resembling dead and moldy leaves, 
warningly striped and nauseous beetles, or moths equipped with giant 
owl-like eyes, they could see all the evidence for a sophistication of 
perceptual ability surely only to be found in man himself: on the 
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536608—60——_30 
