1912.] NATURAL SCIENCES OF PHILADELPHIA. 281 



THE EXPERIMENTAL METHOD OF TESTING THE EFFICIENCY OF WARNING 



AND CRYPTIC COLORATION IN PROTECTING ANIMALS 



FROM THEIR ENEMIES. 



BY W. L. McATEE. 



Contents. 



Introduction 281 



Experiments with Invertebrates (chiefly Insects) 287 



Experiments with Vertebrates...! 289 



Fishes 289 



Amphibia 290 



In Countries other than the United States 290 



In the United States 291 



Toads 291 



Frogs 295 



Salamanders 296 



Reptiles 296 



Experiments in Asia 296 



Experiments in Europe 298 



Experiments in America 298 



Mammals 300 



Mixed Groups of Animals 301 



Birds 318 



Experiments in Europe 318 



Experiments in Africa 325 



Experiments in Asia 326 



Experiments in America 331 



Experiments by Judd and Beal 332 



Summary 356 



Introduction. 



The selectionist theories regarding the significance and the causes 

 of production of the so-called warning, mimicking, and cryptic 

 coloration long preceded a knowledge of the food preferences of 

 insectivorous animals sufficient to warrant such speculations. In 

 fact, this knowledge is still almost entirely lacking for many parts of 

 the world — including the Amazon valley, which is the home of the 

 brightly colored Heliconiid butterflies and their mimics that sug- 

 gested the mimicry theory to H. W. Bates. In 1861, Bates explained 

 the numerous cases of mimicry of the butterflies of this family by 

 butterflies and moths of at least five other families, by stating that 

 the Heliconiidse probably are unpalatable to insect enemies, and 

 that the others disguised in their dress share this immunity. 1 He 



1 Trans. Linn. Soc. Lond., XXIII, 1862, p. 510. 

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