Mr Edwards on Change of Colour in the Chameleon. SIS 



other metallic oxides whicli were capable of producing the same 

 effects. I added, then, various oxides to a watery solution of 

 i&inglass. I subjoin the results of these experiments. The 

 oxides of lead and tin appeared to quicken the development of 

 the thallus ; it appeared so soon as the second day. The oxides 

 of iron, antimony, and zinc, did not appear to me to exercise 

 any influence upon the development of these thalluses, which 

 appeared, as they usually do, at the end of four or five days. 

 The oxides of copper, nickel, and cobalt, considerably retarded 

 their appearance, for they did not show themselves until «the 

 twelfth or fifteenth day. Thus the oxide of mercury, appears 

 to be the only one which prevents the appearance of mouldi- 

 ness.* 



On the Change of Colour in the Chameleon. By H. Milne 

 Edwards, Esq. 



The little reptile which is known under the name of the 

 Chameleon, has been long celebrated for the sudden changes 

 which the colour of its skin undergoes. Hence it has become 

 the popular emblem of man's versatility ; and were we to be- 

 lieve ancient writers, it possesses the marvellous power of suc- 

 cessively assuming the colour of every object with which it 

 comes in contact. It is long, however, since naturalists have 

 stript the history of this little animal of all the fables with which 

 it was adorned ; but it is at the same time true, that, in denying it 

 the property of changing its colour almost without limit, it has 

 decidedly been established, that it undergoes truly remarkable 

 variations ; and is sometimes nearly white, sometimes yellowish, 

 and sometimes again almost black, according as it is asleep, or 

 in its ordinary waking condition, or is excited by anger. 



This singular phenomenon was, without doubt, abundantly 

 calculated to excite curiosity ; and zoologists, of course, en- 

 deavoured to discover the cause of it. On examination, we 

 find that they have furnished a variety of hypotheses more or 

 less plausible ; but they have not, so far as I know, grounded 

 their opinions upon physiological experiments, or anatomical 

 * Annales des Sciences Naturelles. Janvier 1834. 



