CHANGING COLOUKS. 



)93 



Cypris, an insect which was brought from the emerald mines 

 of Muso, in North Granada, and which seems to partake with 

 the gems the full glory of colour. It is scarcely possible to 

 conceive of a living creature that can surpass this insect in abso- 

 lute magnificence of colour. The upper surface is radiant azure, 

 as if composed of a sheet of thin mother-of-pearl. 



When the light falls in the right direction, the colour is so 

 intense that the eye can scarcely endure its radiance. Yet, with 

 a cross light, the dazzling azure becomes dull blue, and if the 



Fig. 335. — Morpho Cypris. 



(Azure and yellow.) 



light be directed from the tip to the base of the wing, the surface 

 becomes brown. Thus, while holding the insect and turning it 

 in different lights, it often happens that either the entire surface 

 is dull blue, or that one wing is glowing azure, while the other 

 is dark brown. The cause of this change of colour is shown by 

 the microscope. The scales are nearly square, and, as they 

 overlap one another, they are slightly curved in the middle. 



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