316 Mr Edwards on Change of Colour in the Chameleon. 



body of the animal. These chameleons often swelled up ex- 

 ceedingly, without exhibiting any change of colour, and at 

 other times these variations occurred, without their being pre- 

 ceded by any change of its size. 



Thus then, direct observation destroys in a moment all the 

 hypotheses, by the help of which naturalists had endeavoured 

 to explain the changes in the chameleon's colour by the effects of 

 the distention, more or less considerable, of its lungs ; but they 

 had hitherto thrown no hght upon the real cause of the pheno- 

 menon. To obtain information on this point, I had recourse to 

 anatomy. 



Immediately after the death of chameleon No. 1., I detached a 

 portion of the skin, upon which were to be found both the dark 

 and red colour already described, and a large yellowish-grey 

 spot, which I submitted to examination under a powerful mag- 

 nifying glass. 



The surface of the skin is, as is well known, thickly set with 

 an immense number of small rounded tubercles, amongst which 

 much finer granulations are to seen. Some naturalists have 

 thought, as before stated, that the changes in the colour in the 

 chameleon depended on the circumstance that these tubercles 

 were yellowish, and the deeper parts of the skin of some other co- 

 lour ; and that when the skin was contracted, they alone were 

 seen, whilst by the distention of the integuments, their points 

 extended themselves, so to speak, over the inferior surface thus 

 brought into view. But the real fact is opposed to this suppo- 

 sition ; for, in those portions of the surface of the body which 

 were most deeply tinged, as well as in those that were clearest, 

 it was exactly underneath these tubercles that the local tint, 

 whatever it was, was the most distinct. 



In those parts of the skin which were of a dark red colour, 

 it was easy to satisfy oneVself with the help of the magnifying 

 glass, that the yellowish-grey colour peculiar to the neighbour- 

 ing parts, had not entirely disappeared, but it was, as it were, 

 somehow marked by a countless number of minute points of a 

 purplish red, more or less deep ; each tubercle seemed covered 

 with a net-work, and, examined with the naked eye, these points 

 seemed to cover all the surface. Between the several tubercles, 

 points of the same colour were also visible, but of a much 



