AUDITORY POWERS OF THE CATOCALA MOTHS; 

 AN EXPERIMENTAL FIELD STUDY. 1 



C. H. TURNER AND E. SCHWARZ. 



HISTORICAL RESUME. 



Near the close of the nineteenth century, Romanes ('91) wrote: 

 "Among insects organs of hearing certainly occur, at least in 

 some, although the experiments of Sir John Lubbock appear to 

 show that ants are deaf. The evidence that some insects are 

 able to hear is not only morphological, but also physiological, 

 because it is only on the supposition that they do that the fact 

 of stridulation and other sexual sounds being made by certain 

 insects can be explained, and Brunelli found that when he 

 separated a female grasshopper from the male by a distance of 

 several meters, the male began to stridulate in order to inform her 

 of his position, upon which the female approached him. I have 

 myself published observations proving the occurrence of a 

 sense of hearing among the Lepidoptera." 



The tone of three fourths of the above paragraph is char- 

 acteristic of practically all of the early works upon the auditory 

 powers of insects. Those men were convinced that insects hear; 

 not because they had experimentally demonstrated it, but for 

 morphological reasons, and because many kinds of insects can 

 produce sounds. They believed that an insect would not be 

 endowed with the power of producing sounds unless the other 

 members of the species could hear. At first in the Orthoptera 

 and later in other groups of insects, peculiar organs were found; 

 consisting essentially of vibratory hairs attached to certain cells 

 that seem to be sensory in nature. In some cases these hairs are 

 in cavities and in others they are not. Such was the nature of 

 the work of Siebold ('44), Leydig ('55), Henson ('66), Lee ('83, 

 '85), Graber ('75, '82), Weinland ('91), Adelung ('92) and others. 

 As late as 1905 Radl expressed the following thought. No matter 



1 For the identification of the species and for the experimental work on C. unijuga, 

 E. Schwarz alone is responsible; the field work was performed jointly; for the plan- 

 ning of the work, for the historical resume and for the method of treatment, C. H. 

 Turner is solely responsible. 



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