94 THE LARGE-NAPED CHAMELEON. 



this phenomenon is that of Dr. Weissenbaum, published in the " Magazine of Natural 

 History" for 1838. The writer had a living Chameleon for some time, and gives the result 

 of his observations in the following words : 



" The remote cause of the difference of colour in the two lateral folds of the body, may 

 be distinctly referred to the manner in which the light acts upon the animal. The state- 

 ment of Murray that the side turned towards the light is always of a darker colour, is 

 perfectly true ; this rule holds good with reference to the direct and diffused light of the 

 sun and moon as to 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 coloured than the other. 



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

 powerful manner than the other, and as the middle line is constantly the line of demarca- 

 tion between the two different shades of colour, 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, without doubt, the 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 darker side, which is constantly more convex than the other. 



Many other circumstances may be brought forward in favour of the opinion that the 

 nervous 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 wishes 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 water, that the faculty of 

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



On the other hand, when the creature is undisturbed, the eye which receives the 

 strongest 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 cautiously approaching my 

 specimen at night with a candle, so as not to awake the whole animal by the shaking of 

 the room, the eye turned toward the flame would open and begin to move, and the 

 corresponding side to change colour, 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 colour 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 upon each other, and so produce the different 

 effects. 



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

 in colour, 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 the tail, which in the male is thick and swollen at the base. 



THEBE 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 Fork-nosed Chameleon, as it is sometimes called. 



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



