QUARRELS AT MEALS. 1G5 



and watched its eating, the Worm appeared after a 

 few moments, aware probably by the vibrations of its 

 huge fellow-tenant's body, that feeding was going on, 

 and not I think by any sense of smell, for a reason 

 which I shall presently adduce. The mode and the 

 place of the Worm's appearance were the same in 

 every case, and it invariably glided to the Crab's 

 mouth between the two left foot-jaws. I was sur- 

 prised to observe what a cavern opened beneath the 

 pointed head of the Nereis when it seized the morsel, 

 and with what force comparatively large pieces were 

 torn off and swallowed, and how firmly the throat- 

 jaws held the piece when it would not yield. Occa- 

 sionally it was dragged quite away from the Crab's 

 jaws, and quickly carried into the recesses of the 

 shell ; sometimes in this case he put in one of his 

 claws and recovered his morsel ; at others he gave a 

 sudden start at missing his grasp, which frightened 

 the Worm and made it let go and retreat ; but some- 

 times the latter made good his foray, and enjoyed his 

 plunder in secret. 



The worm is itself a striking and even handsome 

 animal ; and there is in its colours and their distribu- 

 tion, — two bright white lines running through the 

 whole length on a light red ground, — a curious simi- 

 larity to the colouring of the Crab. 



I have reason to think that the partnership in ques- 

 tion is by no means casual or exceptional, but ordi- 

 nary if not constant. A second Whelk-shell in my 

 Aquarium, surmounted also by a Parasitic Actinia, 

 but which has been deserted by the Soldier, retains 

 a Nereis as its tenant : and I know from experience 



