INSECTS : WIXGS AND THEIK APPENDAGES. 



89 



scales proper arc all marked w'ltli longitudinal lines, 

 very minute and close, but they mostly bear a central 

 band, and sometimes a marginal one on cacli side, of 

 spots set in sinuous lines like the bands on a macker- 

 el's back ; these are probably composed of pigment- 

 granules. 



These from the pretty Six-spot Burnet Ilawkmoth, 

 are nearl}^ opaque, especially those from the red parts 

 of the wings, which have a rich ruddy glow by trans- 

 mitted light. They arc narrow in shape, tapering 

 gradually forward from the foot-stalk, and terminate 

 mostly in two blunt points. The ribs are coarse for the 

 size of the scales, and the depressed spaces are marked 

 with irregular pigment-grains. 



The hairs with which the bodies 

 of Moths are invested arc essentially 

 of the same character as the scales 

 which clothe their wings. Here are 

 examples from tlie glowing sides of 

 the abdomen of that richly coloured 

 insect, the Cream-spot Tiger-mouth 

 {Arctia villica). You see they are 

 simple scales, drawn out to an inor- 

 dinate length and great tenuity ; each 

 has its quill-like foot-stalk, and we 

 may trace on some of them the ribs 

 and transverse dotting, while here we 

 see all intermediate stages between 

 the slenderest hair and the broadly 

 ovate, bluntlv-pointed scales from the battledoor scai.k of ro- 



LYOMIIATLS ALEXIS. 



Wings. 



You are familiar of course M'ith tlie brilliant little 

 Blue Butterfly {Polyommaius Alexis)^ which dances 



