INTRODUCTION. 3 



in search of honey. It appears as if single and solid, bnt 

 is really composed of two exactly similar lateral halves 

 grooved along their iniier surface, so that when placed 

 together the opposing grooves form a fine tube; and to 

 secure them in place, so that the tube shall not leak, the 

 edges of the grooves are delicately notched so as to dove- 

 tail into corresponding teeth on the edge of the opposing 

 groove, by which they become closely interlocked. 



To enable the butterfly to pump into its body through 

 this tube the honey-ed sweets of flowers, the throat at the 

 base of the tube expands into a sac with muscles radiating 

 toward the walls of the head and others encircling it; 

 when the first set of muscles contracts, the interior space 

 of the sac is enlarged ; when the encircling muscles con- 

 tract, it is diminished. By the alternating action of these 

 sets, a pumping process goes on aided by a little flap at the 

 base of the tube which lets the fluids pass in but not out; 

 so tha^, the squeezing of the full sac presses the fluids into 

 the stomach; its enlargement creates a vacuum which 

 causes the honey in the flower to ascend the tube past the 

 valve into the sac. 



The antennaB may be divided into a base consisting of 

 two joints stouter than those beyond; a thread-like stalk, 

 slender and equal, consisting of many joints; and the club, 

 which is composed of the swollen tij), sometimes arising 

 almost insensibly from the stalk, sometimes abruptly; and 

 in the Skippers having usually a recurved hook at the tip; 

 the club is usually at least twice as thick as the middle of 

 the stalk, generally naked beneath and often flattened. 



The eyes are usually very convex, but vary in different 

 groups in this respect as well as in the amount of space 

 they cover; they are ordinarily naked, but sometimes deli- 

 cately hairy, and in the Skippers are overhung by a curv- 

 ing tuft of bristles. The number of facets in the eye is 

 very great, numbering thousands to each eye. 



