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INTRODUCTION 



The subject of color changes in animals was a familiar 

 one to the ancients. Aristotle, in the second book of 

 his History of Animals, declared that the chameleon, an 

 inhabitant of the North Coast of Africa, can acquire 

 either a black color, like that of the crocodile, or an 

 ocherous one, like that of the lizard, or can be spotted 

 with black like the panther. These changes, according 

 to the Stagirite, take place over the whole body of this 

 animal, for the eyes change like the rest and so does the 

 tail. This description, together with certain other de- 

 tails recorded by x^ristotle for this remarkable animal, 

 was repeated almost verbatim by Pliny in the eighth 

 book of his Natural History, to which he added the pop- 

 ular fiction that the chameleon feeds upon air. Pliny 

 also recorded the color changes of the mullet, a Medi- 

 terranean fish much sought after as a delicacy for Ro- 

 man feasts. In the ninth book of his Natural History 

 he wrote that the masters of gastronomy inform us that 

 the mullet while dying assumes a variety of colors and 

 a succession of shades, and that the hue of its red scales 

 growing paler and paler, gradually changes more espe- 

 cially if the fish is looked at enclosed in glass. Thus 

 knowledge of these remarkable color changes was not 

 only a part of ancient lore but was passed on to pos- 

 terity. In Henry the Sixth Shakespeare put into the 

 mouth of the infamous Duke of Gloucester the boast 

 " I can add colors to the chameleon "; and no less a 

 personage than Hamlet, when asked by his uncle-king 

 how fares his health, replied " Excellent, i' faith; of the 

 chameleon's dish: I eat the air." Thus did the Bard 



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