22 THE COMMONER BUTTERFLIES. 



12. The Sekses of Butterflies. 



The power and range of vision in butterflies (and in 

 insects in general) have without doubt been popularly 

 overestimated. Both direct experiments and study of the 

 structure of the compound eye lead to the same conclusion: 

 that while insects have a quick perception of moving objects 

 or of objects among which they are moving, they have no 

 power of distinguishing precise form or delicate distinc- 

 tions of color or patterns, their visual perception being 

 confused or vague. 



The delicacy of the sense of smell in insects, and espe- 

 cially in Lejudoptera, makes full amend for defective vision. 

 The quick advent of males among many tribes to secluded 

 and concealed females, the possession of many odoriferous 

 organs, the evidence that many others exist where the odors 

 are imperceptible to human sense, all point to a delicate 

 and keen perceptive power in this direction. It is alto- 

 gether probable — and no other exjolanation has so great 

 probability — that it is by the exercise of this sense that 

 the j)arent butterfly discovers the proper food-plant for the 

 deposition of her eggs. The organs for this sense are 

 probably resident in the antennae. 



The fondness of butterflies for the honeyed sweets of 

 flowers at once suggests a high development of the sense 

 of taste; for that it is not jmrely a matter of hunger or the 

 need of nourishment maybe seen in the cases so often 

 noted where butterflies fill their bodies until they can 

 scarcely fly, which is far beyond any need of nourishment; 

 or in the groups which continue for hours around a moist 

 spot in a road imbibing the innutritive fluids. The organs 

 for this sense are probably resident in the tongue-2:)apilla?. 



There seem to be no reasons for believing that any high 

 degree of power in hearing is to be found among butter- 



