EXERCISE 106 



All protoplasm is irritable, but not all organisms have special sense organs. While the reactions 

 of organisms to stimulation often bring them into more favorable positions with relation to the environ- 

 ment, not every sensation or every response is necessarily of benefit to the organism. 



In the following table indicate the responses of the organisms named to the different kinds of 

 stimulation, and the value of these responses to them. 



Question. What are some plant and animal reactions that are injurious to the organisms ? 



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