XV. 



I HAVE been observing for several days the move- 

 ments of a Common Shore-Crab, which has been 

 almost all his life under my protection. Although 

 his present dimensions would render such a feat im- 

 possible, when first I shook the little fellow off a 

 bunch of 0. officinalis, he could have crawled with 

 the greatest of ease into the mouth of a small pop- 

 gun. We all know that members of this family are 

 bold and daring in their attacks upon their weaker 

 neighbours; upon each and all they wage a constant 

 predatory warfare. The poor Pholades, however, are 

 the favourite objects of their attacks. On these 

 innocent bivalves the Crustacea successfully prey, 

 unless they are protected by their usual rock-bound 

 citadel, which, of course, they cannot always be. In 

 order to watch the Pholas at work, it is necessary that 

 the siphons should be more or less protruding from his 

 tubular dwelling. If supported, say, to the full depth 

 of his valves, the animal is secure ; for I notice that 

 neither crab nor fish can tear away the gristly ends of 



