CHAPTER XIII 

 NEREIS; A STUDY OF LIFE ON THE SEASHORE 



More than any other part of the earth the seashore has been 

 the place of origin of the diverse tjiDes of animal life. The 

 reason for this is not far to seek if it be granted that a diver- 



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Fig. 1(3. — The rocky shore, worn smooth by the beating of the sea. 



sity of environment favors the origin of a great A'ariety of forms 

 of life. When we realize fully how admirably each organ- 

 ism is fitted to some particular niche in nature, we cannot 

 doubt that the more varied the environment, the more varied 

 the life. Some of the niches which the seashore offers may be 



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