of the Tongue of the Chameleon. 171 



which it is kept by some tendons so attached on a zig-zag form 

 to the outside of the tongue (Fig. 8, B, A) as to act after the 

 manner of a spring; and that its retraction into the mouth 

 might be effected by the action of a longitudinal muscle (C, C,). 

 M. De la Hire offers a sufficient apology for so absurd a sup- 

 position, in acknowledging that he had never an opportunity of 

 examining the structure of the organ. 



The central tube was described by the anatomists of the 

 French Academy as being a nerve which had the power of 

 throwing forth the tongue (meaning the prehensile portion) 

 which was attached to it by elongation itself, and of drawing it 

 back again by contracting. It is a sufficient reply to this ex- 

 planation, that the part alluded to is not a nerve ; and even 

 granting it were so, that nervous structure is no where possessed 

 of powers of elongation and contraction. 



There is a common supposition, that the tongue is extended 

 by inflation with air, and drawn back again by the supposed 

 nerve in its middle, which after having been elongated by the 

 effort, returns it again suddenly to its former state. But this 

 explanation is as untenable as the others, for no opening of com- 

 munication can be discovered between the mouth or trachea 

 and the tongue, through which air could find admission into the 

 organ. 



The Baron Cuvier, who has contributed so much to the ad- 

 vancement of natural science, supposes that the propulsion of 

 the organ from the mouth, and its subsequent retraction, are 

 effected in part by the alternate elongation and shortening of 

 that portion which I have named prehensile, and in part by the 

 advancement and retreat of the os hyoides. The entire process, 

 according to his explanation, is the result of muscular action. 

 With regard to the elongation or shortening of its prehensile 

 portion, which he conceives may be produced by the annular 

 and retractor muscles *, a reference to my account of its struc- 

 ture will shew that no such change in its form can take place. 

 A dense, fibrous, inelastic sheath which surrounds it must effec- 

 tually prevent an alteration being made either in its length or 

 thickness, by any muscular force which it possesses. Even 

 when removed from the body, attempts to stretch it with the 



* licyoin d'Anatomie Coniparec, T. 3. p. 273, 274. 



