Mr. H. N. Turner, writing from personal observation of the phenomenon in a live Chameleon in his possession, says:--"It has been generally imagined that the purpose of the singular faculty accorded to the Chameleon is to enable it to accommodate its appearance to that of surrounding objects." Mr. Turner's observations do not, however, favour the idea, but seem rather to negative it. The box in which Mr. Turner's Chameleon was kept was of deal, with glass at the top, and a piece of flannel laid at the bottom, a small branching stick being placed there by way of a perch. He introduced, at various times, pieces of coloured paper, covering the bottom of the box, of blue, yellow, and scarlet, but without the slightest effect upon the appearance of the animal. Considering that these primary colours were not such as it would be likely to be placed in contact with in a state of nature, he next tried a piece of green calico, but equally without result. The animal went through all its usual changes without their being in any way modified by the colour placed underneath it. The general tint approximated, as may be readily observed, to those of the branches of trees, just as those of most animals do to the places in which they dwell; but Mr. Turner did not observe the faculty of changing called into play with any apparent object. It is only when the light is removed that the animal assumes a colour which absorbs but little of it. Not to go further into the numerous treatises which have been published on this intricate subject without arriving at a just conclusion, we refer to the able and interesting paper of Mr. Milne Edwards, for whose acuteness the solution of this puzzling phenomenon was reserved. The steps by which he first overthrew the received theories on the subject, and then arrived at the cause of the change of colour, is shown in the following results, derived from observing two Chameleons living, and researches after the animals had died, on the structure of their skin, and the parts immediately beneath it. 1. That the change in the colour of the Chameleon does not depend essentially either on the more or less considerable swelling of their bodies, or the changes which might hence result to the condition of their blood or circulation; nor does it depend on the greater or less distance which may exist between the several cutaneous tubercles; although it is not to be denied that these circumstances probably exercise some influence upon the phenomenon. 2. That there exist in the skin of these animals two layers of membranous pigment, placed the one above the other, but disposed in such a way as to appear simultaneously under the cuticle, and sometimes in such a manner that the one may hide the other.