326 



C. H. TURNER. 



These experiments were conducted in the mornings between 

 five and half past seven and in the afternoons between three and 

 seven. On Saturdays and Sundays experiments were sometimes 

 conducted all day long. 



For producing stimuli the following instruments were used: 

 an adjustible organ pipe, with a range for all notes of two octaves 

 and for one note of three; an adjustable pitch pipe, and an 

 Edelmann's Galton whistle. Such moths as responded did so by 

 moving the wings as though about to fly. In the early experi- 

 ments, before I had many moths on hand, each moth was tested 

 with all of these instruments; because I hoped to determine the 

 upper and lower threshold of hearing for each specimen. Later 

 on, partly because I became convinced that there are theoretical 



TABLE I. 



Number: 3-VI-I4: i. Specimen: Callosamia promelhea, female. 

 Place: Confined, under a wire dish cover, on the swinging shelf. 

 Method: At each trial the instrument was sounded five times at intervals of a 

 minute and records made of the moth's behavior. 



Explanation of abbreviations; G.W. means Galton whistle; O.P., organ pipe; 

 P.P., pitch pipe; in the second column, the roman numerals stand for months and 

 the Arabic for days; in the third column, the hours are numbered from i to 24, 

 beginning at i A.M. 



