204 
The other two sets of markings consist of an irregular marbling, 
and a number of full round spots; the latter never appear otherwise 
than as dark upon the ground-colour, and the marbling, which is ge- 
nerally also dark, only occasionally appears a little lighter than the 
ground-colour, and then of a different tone; either may be visible 
without the other, or both may be distinctly traceable. Sometimes 
the marbling will be apparent together with such of the spots as are 
placed within its intervals, those upon the surface occupied by the 
marbling being amalgamated with it. 
When the general colour is light yellow or pale greenish, which is 
the case if the animal be suddenly brought into the light, the elon- 
gated spots, which form two rows on each side, will begin to appear 
of a very delicate purple tint. After that the marbling gradually 
shows itself, and the general tint begins to darken; when some time 
has elapsed a brown colour is assumed, and the elongate spots, at first 
purple of a darker tint than the yellow ground-work, are seen to be 
brown, of a lighter and rather richer tint than that which now per- 
vades the whole. These distinctions may go on increasing, may then 
decrease and again increase ; the spots may appear, may come and go 
with different degrees of intensity, so that the variety of appearances 
presented is almost indefinite. When visited in the day-time, the colour 
is generally brown, sometimes without markings, generally with the 
elongate spots of a lighter tint, and the marbling or the round spots, 
or both, more or less apparent. Occasionally it presents a uniform 
dull olive, and then has no markings. Sometimes it is of a light drab 
colour, with the different marks faintly indicated. The ventral series 
of prominent scales remains constantly white, as stated by Van der 
Hoven, not participating in the changes of the surrounding parts. 
This author does not in any of his plates represent the longitudi- 
nal rows of markings as a decided dark upon the ground-colour, nor 
is the marbling anywhere clearly shown as pervading the whole body ; 
neither does he give the deep brown tint with the marbling as a dark, 
and the longitudinal rows of spots definitively marked as a light. 
I have never seen my specimen present anything like the appear- 
ances delineated in his plates 4 and 5, probably because I have not 
irritated it. 
It has generally been imagined that the purpose of this singular 
faculty accorded to the Chameeleon is to enable it to accommodate its 
appearance to that of surrounding objects, but the observations of 
Van der Hoven seem to negative that idea, and the few experiments 
I have made with that view have not led to any such results. The 
box in which it is kept is of deal, with a glass at the top and a 
piece of flannel laid at the bottom; a small branching stick being 
introduced by way of a perch. I have 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 appear- 
ance 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, I next tried a piece of green calico, but equally without re- 
sult. The animal went through all its usual changes, without their 
