of the Tongue of' the Chameleon. 175 



the OS hyoides is drawn back by the sterno-hyoid, sterno-cera- 

 toid, and omo-hyoid muscles ; the turgeseence of the erectile 

 part subsides ; the pouch on the end is again deepened by the 

 action of the retractor muscles, and the relaxation of the mu- 

 cous membrane on the sides; and the hyo-glossi draw in the 

 tongue, folding up the erectile portion and replacing the pre- 

 hensile on the style. The parts thus arranged, the organ is 

 made fit for the ordinary purposes of mastication by the annular 

 muscle fixing the prehensile portion, and preventing its rotation 

 on the slippery style, and by the hyo-glossi drawing it in the di- 

 rection of the cornua of the os hyoides, so as to obviate any dis- 

 placement forwards. 



The chief objection urged against this theory is the difficulty 

 of conceiving how vascular congestion could affect the elongation 

 with the rapidity ascribed to it during health. This objection, 

 however, does not apply to the act as observed in those animals 

 from which I have drawn my conclusions, for the motion of their 

 tongues was by no means so rapid as to be irreconcileable with 

 such a cause. It was not more rapid than the instantaneous 

 blush on the cheek of youth ; nor more rapid than several other 

 phenomena which are universally allowed to be the result of 

 vascular turgeseence. How far in a state of nature the rapidity 

 of projection exceeds what was observed in those Aveakened by 

 confinement, I cannot determine ; but perhaps the difference 

 may not be so great as is usually believed. Few of our ac- 

 counts on the subject have been given by naturalists on the tes- 

 timony of their own observation ; and it is not going too far to 

 suppose, that it may have been with their descriptions of the 

 chameleon's tongue, as with those given by them of its skin, in 

 which fancy contributed so largely to the colouring : for we 

 must admit, that much of imagination has mingled with their 

 accounts of the organ, when we find it described, and even 

 figured, as in the act of turning backwards and seizing objects 

 placed on its tail, a range of motion by no means compatible 

 with its structure or cause of action. 



I have already observed — and it may partly account for the 

 reputed quickness of the tongue — that at one period of the elon- 

 gation the rapidity, even in my chameleons, was such as might 

 justly be compared with that of an arrow, but then it was only 



