Seaside Natural History 



83 



SEASIDE NATURAL HISTORY. 



No. I. — Sea Anemone and Hermit Crab. 



Our frontispiece (copied from Johnston) illustrates in one 

 picture two of the many very curious life habits which have 

 been acquired by some of the lower animals. A hermit crab 

 is shown in possession of a large shell as its house, and 

 upon the outside of this house two large sea anemones 

 have planted themselves. This partnership possession of 

 stolen property is not only not unusual, but it is the 

 ordinary course of life of the two animals. The hermit 

 crab (Paguvus) has, in the first place, been so long in the 

 habit of taking an empty shell for its home that its own 

 structure has become modified, and the hinder parts of its 

 body are now soft, and unprotected by the shelly armour 

 common to its species. The anemone, on its part, has 

 acquired such a strong preference for a shell which can 

 travel about that it is rarely found in any other position. 

 Its habit has earned for it the name of parasite. It is the 

 Sagartia or Actinia parasitica of zoologists. Sometimes it is 

 found on an empty shell and sometimes on a fixed stone, but 

 these locations are exceptional. The crab carries its shell 

 about with it, and the anemone apparently enjoys riding. It 

 is quite probable that the companions are of advantage to 

 each other. The anemones undoubtedly serve the crab's 

 purpose in concealing his dwelling-place. The anemones 

 may also obtain food from what the crab rejects. It is 

 believed that crabs will seek the anemones and endeavour to 

 get them placed on their shells. It is quite certain the crab 

 never molests the anemone, whilst very often, when small, the 

 latter is attached close to the lip of the shell. Of this latter 

 position illustrations are given in the " Guide to the Naples 

 Aquarium," where living specimens may always be seen. Mr. 

 G. B. Sowerby, in his " Popular History of the Aquarium," 

 gives a coloured figure in his plate xi., and at page 104 writes : 

 " He (the anemone) usually chooses a Buccinum inhabited by 



