92 THE LARGE-NAPED CHAMELEON. 



artificial light. Even when the animal was moving in the walks of my garden, and happened 

 to come near enough to the border to be shaded by the box edging, that side so shaded would 

 instantly become less darkly colored than the other. 



"Now the light in this way seldom illumines exactly one half of the animal in a more 

 powei'fid manner than the other, and as the middle line is constantly the line of demarcation 

 between the two different shades of color, we must evidently refer the different effects to two 

 different centres, from which the nervous currents can only radiate, under such circumstances, 

 towards the organs respectively situated on each side of the mesial line. Over these centres, 

 withoxit doubt, tlie organ of vision immediately presides ; and, indeed, we ought not to 

 wonder that the action of light has such powerful effects on the highly irritable organization 

 of the Chameleon, considering that the eye is most highly developed. The lungs are but 

 secondarily affected, but they are likewise more strongly excited on the darJcer side, wJdch is 

 constantly more convex than the other. 



"Many other circumstances may be brought forward in favor of the opinion that the ner- 

 vous currents in one half of the Chameleon are going on independently of those in the other ; 

 and that the animal has two lateral centres of perception, sensation and motion, besides the 

 common one in which must reside the faculty of concentration. 



"Notwithstanding the strictly symmetrical construction of the Chameleon as to its two 

 halves, the eyes move independently of each other, and convey different impressions to their 

 different centres of perception ; the consequence is, that when the animal is agitated, its 

 movements appear like those of two animals glued together. Each half ^vishes to move its 

 own way, and there is no concordance of action. The Chameleon, therefore, is not able to 

 swim like other animals ; it is so frightened if put into watei', that the faculty of concentra- 

 tion is lost, and it tumbles about as if in a state of intoxication. 



"On the otlier hand, when the creature is undisturbed, the eye which receives the strong- 

 est impression propagates it to the common centre, and prevails on the other eye to follow that 

 impression, and direct itself to the same object. The Chameleon, moreover, may be asleep on 

 one side and awake on the other. When caiitiously approaching my specimen at night with a 

 candle, so as not to awake the whole animal by the shaking of the room, the eye tui'ned 

 toward the flame would open and begin to move, and the corresponding side to change color, 

 whereas the other side would remain for several seconds longer in its torpid and changeable 

 state, with its eye shut." 



It seems probable that the change of color may be directly owing to the greater or less 

 rapidity of the circulation, which may turn the Chameleon from green to yellow, just as in 

 ourselves an emotion of the mind can tinge the cheek with scarlet, or leave it pallid and death- 

 like. Mr. Milne Edwards thinks that it is due to two layers of pigment cells in the skin, 

 arranged so as to be movable vtpon each other, and so produce the different effects. 



The young of the Chameleon are produced from eggs, which are very spherical, white in 

 color, and covered with a chalky and very porous shell. They are placed on the ground under 

 leaves, and there left to hatch by the heat of the sun, and the warmth produced by the 

 decomposition of the leaves. The two sexes can be distinguished from each other by the 

 shape of tlie tail, which in the male is thick and swollen at the base. 



There are nearly twenty species of Chameleons known to zoologists at the present day, all 

 presenting some peculiarity of form or structure. One of the most remarkable species is the 

 Large-naped Chameleon, or Pork -nosed Chameleon, as it is sometimes called. 



This creature inhabits Madagascar, that land which nourishes so many strange forms of 

 animal life. It is also found in India, the Moluccas, and Australia. When full grown, the 

 muzzle of the male is very deeply cleft, or forlved, the two branches diverging from each 

 other. The female has no horns, and in the male they are short and blunt while the creature 

 is young, not obtaining their fidl length and sharpness until it has attained full age. These 

 curious forked projections belong to the skull, and are not merely a jaair of prolonged scales 

 or tubercles. 



