On the Structure and Mechanism of the Tongue of the Chameleon. — 

 By John Houston, Esq., Member of the Royal College of Sur- 

 geons in Ireland, Conservator of the Museum, and Demonstrator 

 of Anatomy in the School of Surgery, &c. — Communicated by 

 the Lord Bishop of Cloyne. 



Read April 28, 1828. 



JL HAT the Chameleon possesses the power of suddenly darting out 

 its tongue in a remarkable manner, for the purpose of seizing the 

 insects on which it feeds, is a fact which has been long admitted ; 

 but notwithstanding that so singular a phenomenon has attracted 

 the attention of the most distinguished anatomists, it appears to me 

 that neither the cause, nor mode of elongation in the organ, have 

 ever yet been satisfactorily explained. 



Two of these animals having been lately presented to me, in suf- 

 ficient health to take food in their natural way, an opportunity, such 

 as rarely occurs, was afforded me, both of observing their tongues 

 in the act of elongation during life, and of making a most satisfac- 

 tory examination of their structure immediately after death. I there- 

 fore entertain a hope that the facts which I have collected, under 

 such favourable circumstances, may be calculated to remove much 

 of the obscurity in which the subject has been hitherto involved. 



The animals were brought from Malaga in the month of Oc- 

 tober 1826. They corresponded in characters to the Lacerta 

 Chameleon of Linnaeus. One measured twelve inches in length, the 

 tail included, the other ten. Both were females, and contained 

 numerous ova, which could be felt through the thin parieles of the 



VOL, xv. F F 



