474 THE POPULAR SCIENCE MONTHLY. 



make a paste of tliem with the addition of glue, which is pompously 

 named " Eastern essence." This is put inside glass beads, and gives 

 them the native whiteness of pearls. 



Many observations have been made lately by our naturalists as to 

 the defense which color supplies to animals : hares, rabbits, stags, and 

 goats, possess the most favorable shade for concealing them in the 

 depths of the forest or in the fields. It is well known that when the 

 Volunteer corps were enrolled, and the most suitable color for the 

 riflemen was discussed, it was supposed to be green. Soldiers dressed 

 in different shades were placed in woods and plains, to try which 

 offered the best concealment. Contrary to expectation, that which 

 escaped the eyes of the enemy was not green, but the fawn color of 

 the doe. Among hunting quadrupeds, such as the tiger, the leopard, 

 the jaguar, the panther, there is a shade of skin which man has always 

 been anxious to appropriate for his own use. The old Egyptian tombs 

 have paintings of the negroes of Soudan, their loins girt with the fine 

 yellow skins for which there is still a great sale. All the birds which 

 prey upon the smaller tribes, and fishes like the shark, are clothed in 

 dead colors, so as to be the least seen by their victims. 



There is an animal which, for two thousand years, has excited the 

 curiosity and superstition of man by its change of color — that is, the 

 chameleon. No reasonable observation was ever made upon it, until 

 Perrault instituted some experiments in the seventeenth century. He 

 observed that the animal became pale at night, and took a deeper 

 color when in the sun, or when it was teased ; while the idea that it 

 took its color from surrounding objects was simply fabulous. He 

 wrapped it in different kinds of cloth, and once only did it become 

 paler when in white. Its colors were very limited, varying from gray 

 to green and greenish brown. 



Little more than this is known in the present day ; under our skies 

 it soon loses its intensity of color. Beneath the African sun, its liv- 

 ery is incessantly changing ; sometimes a row of large patches ai^pears 

 on the sides, or the skin is spotted like a trout, the spots turning to 

 the size of a pin's head. At other times, the figures are light on a 

 brown ground, which a moment before were brown on a light ground, 

 and these last during the day. A naturalist speaks of two chamele- 

 ons which were tied together on a boat in the Kile, with sufficient 

 length of string to run about, and so always submissive to the same 

 influences of light, etc. They offered a contrast of color, though to a 

 certain degree alike ; but, when they slept under the straw chair 

 which they chose for their domicile, they were exactly of the same 

 shade during the hours of rest— ^a fine sea-green that never changed. 

 The skin rested, as did the brain, so that it seemed probable that cen- 

 tral activity, thought, will, or whatever name is given, has some effect 

 in the change of color. The probability is that, as they become pale, 

 the pigment does not leave the skin, but that it is collected in spheres 



