112 THE COCKROACH. 



Will observes that the organs described satisfy the essential 

 conditions of a sense of taste. The nerve-endings pass free to 

 the surface, and are thus directly accessible to chemical stimulus. 

 Further, they are so placed that they and the particles of food 

 which get access to them are readily bathed by the saliva. 

 Moistened or dissolved in this fluid, the sapid properties of food 

 are most fully developed. 



The sensory pits and bulbs appropriated to taste are believed 

 to be unusually abundant in the social Hymenoptera. 



Sense of Hearing in Insects. 



The auditory organs of Insects and other Arthropoda are re- 

 markable for the various parts of the body in which they occur. 

 Thus thev have been found in the first abdominal segment of 



/ tj 



Locusts, and in the tibia of the fore-leg of Crickets and 

 Grasshoppers, and more questionable structures with peculiar 

 nerve-endings have been described as occurring in the hinder 

 part of the abdomen of various larvae (Ptij diopter a, Tabanus, Sec). 

 The auditory organ of Decapod Crustacea is lodged in the base 

 of the antennule, that of Stomapods in the tail, while an 

 auditory organ has been lately discovered on the underside of 

 the head of the Myriopod Scutigera. 



Auditory organs are best developed in such Insects as 

 produce sounds as a call to each other. The Cockroach is 

 dumb, and it is, therefore, not a matter of surprise that no 

 structure which can be considered auditory should have ever 

 been detected in this Insect* 



The sensory hairs of the skin have been already noticed 

 (p. 31). 



*For a popular account of auditory organs in Insects, see Graber's Insekten, 

 Vol. I., page 287 ; also J. Midler, Vergl. Phys. d. Gesichssiun, p. 439 ; Siebold, Arch. 

 f. Naturg., 1844; Leydig, Midler's Arch. 1855 and 1860; Hensen, Zeits. f. wiss. 

 Zool., 1866; Graber, Denkschr. der Akad. der wiss. Wien, 1875; and Schmidt, 

 Arch. f. mikr. Anat. , 1875. 



