THE TRIBE OF THE ORANGE-TIPS 95 



collector will find joy in possessing. It is easily recognized 

 by its general white color, which in the female is reHeved 

 only by a distinct black mark on the upper surface of the 

 front wings and a row of marginal markings upon all the 

 wings. The male is slightly smaller and is at once known 

 by the orange blotch on the outer angle of the upper 

 surface of the front wing. This outer angle projects 

 into a distinct point which gives the species its name 

 Falcate. {See plate, page 256.) 



Dr. J. L. Hancock has described in a most interesting 

 manner the way in which this Orange-tip loses itself among 

 the flowers of rock cress. In northern Indiana he found 

 this butterfly abundant in April at the time of the blossom- 

 ing of Arahis lyrata. The butterflies would be flying 

 about, easily seen in the air. Then they would suddenly 

 disappear and could be found only after the most careful 

 search. They had simply lit upon the flower heads, when 

 the flower picturing of the under surface of the wings 

 blended perfectly with the appearance of the clustered 

 flower. 



"The green markings of the under side of the wing," 

 writes Dr. Hancock, "are so arranged as to divide the 

 groimd 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 effectiveness 

 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 pinl^ outside the base of the petals. All in all, 

 the adaptation of insect to flower here displayed is one of 

 rare exquisiteness."* 



*"Nature Sketches in Temperate America", p. 83. 



