PROTECTIVE RESEMBLANCE, WITH EXAMPLES 83 



An Illusive Butterfly, 

 AND ITS Flower Protector 



|N one of my excursions to the sand dune 

 region of Indiana, in April, I occasionally 

 saw a small white butterfly flit about in 

 the air. When it descended near the ground it sud- 

 denly disappeared so completely that I was at first at a loss to 

 explain the cause. I afterwards discovered that the deception 

 practised had been caused by the butterfly alighting on the 

 little white flowers of Arahis lyraia. The resemblance of this 

 butterfly to these flowers is so remarkable that e\'en a trained 

 eye would easily overlook this insect in nature. When I came 

 near, the insect was found with its wings folded together, and 

 it was resting upon the small, pure white flower heads. In this 

 position the protection was heightened by the disposition of 

 the yellowish green markings on the underside of the lower 

 wings. I seized upon the opportunity thus afi"orded to make 

 a drawing of the insect shown in the colored plate. 



The green markings of the imderside of the wings are so 

 arranged as to divide the ground color into patches of white, 

 which blend with or simulate perfectly the petals of the clustered 

 flowers. The eyes of the butterfly are delicate, pale green, 

 and the antennae are whitish, all of which adds to the effective- 

 ness of the blend. The flowers of Arabis have white petals, 

 with the centre yellowish green as is also the calyx. There is 

 a shade of pink outside the base of the petals. All in all, the 

 adaptation of insect to flower here displayed is one of rare 

 exquisiteness. 



One day, in May, I studied the behavior of three of these 

 little butterflies, which are known by scientists as Anthocharis 



