170 



H. C. STEVENS 



3. The influence of the color of the environment upon the color 

 of the material used in decoration. — The experiments of this 

 section were devised to determine whether the color of the 

 material used by the crab in decoration bore any direct rela- 

 tion to the color of the environment. The same four colored 

 aquaria as were used in the experiments upon the chromo- 

 kinetic resonance were employed here. The colors were red, 

 yellow, green and blue. A black aquarium was added, as it 

 was stated by Minkiewicz that the animals do not decorate 

 themselves in black aquaria. The general plan of the experi- 



R Y G B W 

 Figure'6. Shows the curve of distribution of the reactions of Table VI 



ments consisted in carefully stripping off all detachable decora- 

 tions from five individuals and placing each of them in one of 

 the colored aquaria. Colored tissue papers of the same dimen- 

 sions were also placed in the aquaria. The animals were left 

 in the aquaria for a period of several hours, usually over night. 

 Three series of experiments, in which five different crabs were 

 used in each series, furnish the evidence upon which our con- 

 clusions are based. 



First Series 



IX-3-1912. 12:30 P. M. Five individuals were carefully 

 cleansed of all algae, hydroids, etc. Ten pieces, 5x5 mm., 

 of each of five colored papers were placed in the aquaria. The 



