62 CANCERID^. 



as dead fish, and the like ; and it is exceedingly probable 

 that the crabs discover their food rather bj the smell than 

 by sight, or, at least, by an impression made by the dif- 

 fusion of odorous particles emanating from it, and diffused 

 through the water. Thus they detect the bait which is 

 often placed in such situations that it cannot be seen by 

 them at any distance, and which consists generally of pieces 

 of fish, in which decomposition has already commenced. 

 Mr. Couch, indeed, states in his "Cornish Fauna," that " It 

 is found that the freshest (bait) only will attract the crab, 

 whilst for the lobster it is best when hung for several days 

 to become tainted." And this may doubtless be true to 

 a certain extent ; but I have often seen crabs taken with 

 lobsters in pots in which the bait was far from being sweet. 

 The period of life at which the " Bon crab," as the female 

 of this species is termed along the western coast, begins to 

 breed is, according to Mr. Couch, when the carapace is 

 about three inches across. The male seeks the female at 

 various seasons ; but it would appear that in this, as in 

 the case of the Carcinus manas, this often takes place im- 

 mediately after her exuviation, and that the male watches 

 for the completion of this process, when the female is in 

 a soft and unprotected state. My friend Mr. Richard 

 Couch, thus writes to me on this subject. " When the 

 female retires for exuviation, she is generally accompanied 

 by a male ; and when the shell is removed impregnation 

 takes place. If the male be discovered and removed, an- 

 other will be found to have taken his place after the 

 following tide, and this will be repeated for many times in 

 succession." The spawn is carried by the parent for a 

 considerable period, and is deposited " at all seasons of 

 the year," according to Mr. Couch ; Mr. Hailstone says 

 in March ; but it is most probable that it occurs during 



