179 



ill death it became dark, even to blackness, displayed most satis- 

 factorily the great abundance of its vessels. 



These observations on the skin I have deemed it right to make, 

 as they appear to confirm the opinion entertained by some physiolo- 

 gists, that its changes in colour are produced by vascular turges- 

 cence, just as the increased redness in blushing is caused by a rusli of 

 blood to the cheeks. The colour of the blood appearing through the 

 semitransparent skin, and modified by the various permanent colours 

 of that structure, is sufficient to account for every diversity of tint which 

 the chameleon exhibits. I have been induced more particularly to 

 offer these remarks in this place, because from the facts which I have 

 noticed regarding its tongue I have been led to infer, that the pecu- 

 liarities of that organ are all referrible to the same general cause, viz. 

 vascular turgescence. 



By keeping my chameleons in an equable temperature of about 

 summer heat, I succeeded in preserving them both alive for upwards 

 of two months, during which I had ample opportunities of observing 

 the action of their tongues in the prehension of the insects on which 

 they fed almost daily. 



When a fly so maimed as not to be able to escape, but still suffi- 

 ciently vigorous to move its legs or wings, was so placed that its 

 fluttering might attract the chameleon's attention, the animal ad- 

 vanced slowly until within tongue's reach of it, then steadying itself 

 like a pointer, sometimes stretching out its tail, sometimes fixing it 

 against an adjacent body, and directing both eyes steadfastly on the 

 prey, it slowly opened its mouth, and suddenly darted forth its 

 tongue, which advancing in a straight line, seldom failed of striking 

 with its glutinous cupped extremity the object aimed at. But even 

 when the point happened to err, the prey did not always escape, 

 being, nevertheless, sometimes secured by a similar adhesive matter. 



F f2 



