of the Antenna of Insects. 269 



man, the membrane connecting the toes of a bat, or of a duck, 

 the prehensile tail of many tree-climbing mammals, the adhe- 

 sive foot of the ceiling-wandering fly, we cannot fail to re- 

 mark how nicely each peculiarity of structure is adapted to 

 its destined end. 



Throughout creation, wherever it has seemed good to Pro- 

 vidence, in his never-ceasing care for his manifold creatures, 

 that some function should be exercised in an extraordinary 

 degree, there has He bestowed a corresponding instrument, 

 not of casual form, not of fortuitous situation, but of form and 

 site in every respect best adapted to the function for the due 

 performance of which it was called into existence. 



Here then let us enquire what form of instrument is best 

 adapted to the faculty of hearing ; and it must be distinctly 

 understood that the question does not extend to the auditory 

 faculty itself, but to the external portion of the instrument, or 

 that part which is entrusted with the reception and transmis- 

 sion of sound. Most of the higher mammals are known to 

 possess the faculty of hearing, in a very superior degree. — 

 We have ample opportunity of observing the acknowledged 

 instrument of hearing, which these possess. The result of 

 such observation is nature's own reply. The ear of animals 

 is, without doubt, infinitely better adapted to its office, than 

 any artificial instrument which theory might devise or that 

 science could perfect. 



The ear of higher animals is, as far as I am aware, without 

 exception, a hollow conch, either sunk in the head itself, or 

 attached to the external surface of the head. At the bottom 

 of this conch is a very obvious aperture, passing completely 

 into the head, where it communicates with the seat of the 

 auditory faculty. On the size of the external conch depends, 

 in great measure, the quantity of sound received, a fact prov- 

 ed by the application of the hand to our own ear, after the 

 manner of persons who are deaf; thus proving, beyond a 

 doubt, that a large external conch is the form of instrument 

 best adapted for the reception and transmission of sound. — 

 We conclude, not only rationally but inevitably, for we can- 

 not avoid it, that mice, hares, and other animals remark- 

 able for the acuteness of their hearing, are indebted for that 

 very acuteness to the extraordinary aevelopement of the ex- 

 ternal portion of their auditory instrument. 



Man is perfectly insensible to sounds which the timid hare 

 hears with painful distinctness ; and the poor tortoise, unfur- 

 nished with an external conch, takes no heed of sounds that 

 are readily perceptible by man. In this again is the Creator's 

 never-slumbering care for the welfare of his creatures, admi- 



