Social Life in the Salt-JVater JJ'orld 21 



different parts of the world. It Is well known that the 

 differences between the tide levels of continental seas 

 are greater than those to be observed on the shores of 

 oceanic islands. Now this is also due to the irregular 

 distribution of the land which has a tendency to deflect 

 the wave crests, causing them to pile higher than they 

 would do in the open sea. But it so happens that dif- 

 ferences occur on the same coast line. High tides are 

 especially noticeable where they break into gradually 

 narrowing estuaries and other channels; the incoming 

 water, being compressed laterally, is consequently in- 

 creased in height. Thus, in Hempstead Harbor, which 

 receives the retarded waters of the Sound, the mean 

 variation of the tides is about six feet, but in the Bay 

 of Fundy where the incoming tide piles up with great 

 force, it is said the water reaches the extreme height 

 of ninety feet. 



Now, I have gone into this matter of the tides at 

 some length not alone because of its interest to those 

 making their first acquaintance with the sea, but also in 

 order better to visualize for the reader the funda- 

 mental nature of an element that has largely to do with 

 the interpretations we shall make of the strange habits 

 prevailing among many dwellers of the shore. 



Undoubtedly, the greatest attraction of the sea- 

 shore for the collector and naturalist is at the time 

 of the ebbing of a spring tide. As the retreating 

 waters lay bare the land, a promiscuous multitude 

 makes its appearance. From all directions come crea- 

 tures of every description. Through the air, from out 

 of the earth, and over the land they arrive: birds, in- 

 sects, and crustaceans. Mollusks, too, and worms and 



