CHAPTER V. 



PROTECTIVE MIMTORY. 



Mr. Bates' Theory. 



The theory of warning colours is^ believed to obtain very 

 strong support from a series of remarkable facts of which 

 an adeixuate explanation was first offered by Mr. Bates.* 



This naturalist spent many years in South America, being- 

 principally engaged in studying the Lepidoptera of that 

 country. Among the most abundant butterflies in the 

 Amazonian region are those of the famih' Heliconidaj ; the 

 jn-evailing pattern of these insects' wings is shown in the ac- 

 companying woodcut (fig. 24). The contrast between yellow 

 and black suggests at once that they belong to that group 

 which are protected from attack through being distasteful : 

 this suggestion is, to a certain extent, borne out by Mr. Bates' 

 observations. He found in the first jdace that they could 

 secrete from certain glands in the abdomen a disagreeably 

 smelling fluid ; it does not, however, follow from this fact 

 alone that the butterthes would prove disagreeable to the 

 palate of a lizard or a bird : many animals are attracted b_\ 

 odours which to us appear in the highest degree objectionable. 

 An attentive observation of the butterflies convinced both 

 Mr. Bates and BIr. ^Vallace that they were avoided, or at 



' Traiwactioiin nf the Liiiwaii Sucii;/. vol. xxiii. 



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