Gadow on Coral Snakes 
could also distinguish them. . . . Quite often, 
without even searching for them, I can see 
cabbage whites and other butterflies asleep on 
perches to which they by no means assimilate.” 
Mr G. A. B. Dewar suggests that the safety of 
the resting butterfly lies in “the position, the 
couch on high, . . . not the mask of colour or 
marking.” 
Two short visits to Southern Mexico sufficed 
to show Dr Hans Gadow that some of the com- 
monly accepted explanations of colour phenomena 
are not the correct ones. 
Thus writing of coral snakes, he says, on 
page 95 of Through Southern Mexico: ‘They 
are usually paraded as glaring instances of 
warning colouration, but I am not at all sure 
whether this is justifiable. Certainly these Z/aps 
are most conspicuous and beautiful objects. 
Black and carmine or coral red, in alternate 
rings, are the favourite pattern; sometimes with 
narrow golden-yellow rings between them, as 
if to enhance the beautiful combination. But 
these snakes are inclined to be nocturnal in their 
habits, and, except when basking, spend most 
of their time under rotten stumps, in mouldy 
ground, or in ants’ nests in search of their prey, 
which must be very small, to judge from the 
size of the mouth.” 
Dr Gadow goes on to show that although 
black and red are very strong contrasts in the 
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