358 THE FACULTY OF HEARING. 



Prof. Vitus Graber in his exhaustive monograph (Vienna 1875), 

 expresses himself, after prolonged study of the anatomy of the organ 

 in question, doubtfully regarding its function. If it be a special 

 musical ear, he maint:iins that some other additional acoustic organ 

 must exist, and further affirms that if other auditory organs exist 

 in the mute species, they must also exist in the species which 

 possess tympanal organs. It is probable, he asks, that the field 

 cricket recognises with its tympanal organ not only the cry uttered 

 by its kind, but also all other sounds (vibrations communicated 

 through the air) by which it is surrounded, while the wingless 

 cricket {G. aptems) which has no tympanal organ must, if it 

 recognises amj sound, do so by help of some different apparatus 

 placed elsewhere in the body. 



Now it may seem strange that those who have made a special 

 study of this organ, and most thoroughly understand its structure 

 as well as the circumstance of its occurrence or non-occurrence in 

 the different species, should be most divided in opinion respecting 

 its function. But the story may well serve to point a moral of 

 some significance to the naturalist, namely, that provisional 

 conclusions are not to be readily accepted for final settlements. 

 Popular settlements of such questions are rendered easy by the 

 absence of the restraints and corrective methods of science. And 

 the existence or presence of a sense and organ of hearing being a 

 mere question of evidence, and having been long under observation^ 

 is supposed therefore to be perfectly understood. But here we 

 have the insect ear asserted by different authorities to be located in 

 the antennae, on the side of the thorax, below the knee and even 

 in the foot. And while some doubt the very existence of such 

 an organ, others have not a suspicion even that its different type as 

 an instrument, and the different acoustic conditions of its action, 

 may render it entirely unrecognisable. 



The ordinary grounds of our conclusion are firstly, the observation 

 of some outward resemblance to, or analogy with known organs ; 

 secondly, observation of the creature's cries, gestures, and actions, 



