Miscellaneous. 21 1 



this feedinp; lasts the annelid pivos no external sign of life: it 

 awaits the favourable moment. 



lUit the procedure is different when we give the crab u morsel of 

 l.iifre size, as, for instance, u half or a quarter of a cockle {Cardtarn ). 

 Well pleased with this prize, the crab is seen to masticate it 

 forthwith with animation; it even protrudes a portion of its body, 

 and feeds, if I may be perniitved to use the expression, like a glutton. 

 But almost immediately, between the ceithalothorax and the bases 

 of the limbs on the right side, tlu; anterior portion of the worm is 

 seen to make a slow forward movement. The creature, without 

 hesitation, proceeds to explore its comrade's mouth ; on cncouutei- 

 iiig the morsel of cockle there, it ni[)s it forcibly with its powerful 

 mandibles and thenceforth does not relax its hold. Retracting its 

 body, it draws the booty to itself. 'J'heu one of two things 

 ha]ti)ens : either the hermit-crab also clings to the prey, without 

 noticing, moreover, the cause of its in)i)ending loss, and the annelid 

 redoubles its ettorts so etlectually that the fragment is tinally torn in 

 two ; whereupon the worm drags its portion into the interior of tbt3 

 shell, to devour it unmolested. Or else the crab lets go its prey, 

 and the annelid carries it off bodily ; in this manuer 1 have seen 

 the worm take away a Cardiiun almost whole, so that it could 

 not even make it pass through the narrow orifice left between the 

 crustacean and the shell. By dragging very hard, however, the 

 annelid almost always succeeded in accomplishing its purpose. 



There is no need to believe that the worm perceives the near 

 ]ircsence of prey by smell, for, as I have been able to determine by 

 withdrawing it from the shell, its organs of sense are greatly dulled. 

 It is curious to find that it is the hermit-crab itself that, uncon- 

 sciously of course, informs its comrade of the presence of prey of 

 considerable size ; the irregular movements in which the crusta- 

 cean indulges indicate to the annelid that it is time to show itself: 

 the worm is never seen to emerge at any other time. Another fact 

 of interest to be noted is the inditl'erenee of the crustactan with 

 regard to the robber with which it lives and which, to use a popular 

 expression, comes to "snatch tlie morsel 6ut of its mouth." I have 

 often seen the annelid, after the hermit-crab had inadvertently let 

 its prey fail, introduce its head and the foremost aniiuli of its body 

 between the maxillipeds and right into the mouth of the crustacean. 

 Ap[>arently nothing would have been easier for the latter than to 

 ingest the worm and to rid itself of it once for all ; but it left it 

 absolutely alone. The NvreUcinis pro'its by the oj)portunity to 

 devour the fragments of food that still remain in the mouth of the 

 crab, and to carry them off into its retreat. 



The above observations were made in a(iuaria. There is no 

 doubt, considering their fretjuency, that the phenomena take place 

 in tlie same way in a state of nature at the bottom of the sea. The 

 annelid feeds upon the largo substances that the hermit-crab intends 

 to devour. But perhaps it will be asked whether, in addition, the 

 worm docs not eat, if not the whole, at least a portion of the fajces 



