THE BIOLOGY OF THE 

 SEA-SHORE 



CHAPTER I 



Animal Associations and their Characteristics 



It is the purpose of this book to study the animals, and to 

 some extent the plants, of a certain well-defined area — the 

 sea-shore — in relation to their physical environment and 

 to one another. In other words, we are to deal with the 

 plants and animals of the sea-shore not as isolated units, 

 but as an association. The study of animal associations 

 forms part of a wider subject now usually known as ecology 

 (Greek ot/co?, a house), a term proposed by Haeckel to 

 cover the relations of the animal to both its organic and 

 inorganic environment, particularly its relations, whether 

 friendly or hostile, to those animals or plants with which 

 it comes into contact. Another term covering more or 

 less the same ground is " bionomics " ; it is gradually 

 passing out of use. Inasmuch as ecology is concerned 

 strictly with the living organism and its responses to 

 the environment, it may be said to coincide more or less 

 completely with what we understand by biology when this 

 term is used, as it so frequently is, to lay emphasis on the 

 living as distinguished from the purely morphological aspect 

 of the organism. It is in this sense that we employ the title 

 " The Biology of the Sea-shore." 



As a branch of zoological study, animal ecology, though 

 it has only recently begun to attract attention, is undergoing 

 rapid development, particularly at the hands of American 



