BUTTERFLY SOUNDS 93 



unobserved, just at my feet. I instantly stopped 

 motionless to see whether they would settle again, 

 when one of them, which had flown to a short 

 distance, turned and flew rapidly back straight at 

 my face, turning only when within three or four 

 inches of my nose, and then suddenly whisking 

 off with a distinct '' click " at turning. 



All the instances thus far given relate to the 

 family Nymphalidae, and therefore the following 

 instance recorded by Rev. A. E. Eaton of Eng- 

 land is of unusual interest. He states that he 

 heard Parnassius apoUo make a rustling noise by 

 " slowly flapping her wings " while clinging to a 

 flower, " and scraping the hinder pau' with her 

 four posterior legs, which were thrust backwards 

 simultaneously each time that the wings opened ; " 

 it continued to do this even after ihe front wings 

 were firmly held, but stopped when the hind wings 

 were seized. 



The only persons who seem to have endeavored 

 to discover the cause of these sounds are the late 

 Mr. Doubleday and Messrs. Swinton and Hamp- 

 son. Mr. Doubleday examined the species of the 

 genus Ageronia in the British Museum in vain for 

 any sufficient cause drawn from the external struc- 

 ture of the animal. He found certain peculiarities, 



