Crabs, Lobsters, etc. 



A very interesting experiment has been carried out 

 with the hump-backed shrimp. As we have just mentioned, 

 he turns pale at night ; it is not very surprising, therefore, 

 to find that if he be taken into a dark room he rapidly 

 blanches. Now comes the extraordinary part of the 

 experiment by keeping the shrimp in the dark for 

 several days it will be found that it changes from a light 

 to a dark shade by turns, and, furthermore, these alternate 

 colour changes correspond exactly to the hours of night 

 and day. That is to say, although the little creature, by 

 reason of its being in the dark, never comes under the 

 influence of changes in the intensity of light, it still retains 

 its old habit of turning pale when the hours of night are 

 at hand and becoming darker with the day. 



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