348 THE AQUARIAN NATURALIST. 



intervening between the old shell and the body of the 

 animal, and then the subsisting shell opening hori- 

 zontally between the hind pairs of legs allows the con- 

 fined crab to escape, clothed in its new integuments. 



To follow the course of this remarkable process is 

 extremely interesting, and will be witnessed, at least 

 on the first time of its occurrence, with great surprise. 



"I had preserved," says Sir J. Dalyell, "a middle- 

 sized specimen of the Cancer (Carcinus) Manas for 

 several months, which had become very tame and 

 familiar. The heat of a sultry summer's day induced 

 me to put it outside the window of my study in a 

 capacious vessel of sea- water, where it remained during 

 the night. Next morning, when thinking little of the 

 matter, a crab, lying on its back in the tank, struck 

 my view, and beside it stood one of larger dimensions, 

 its very image. I hastily concluded that a stranger 

 had been introduced ; but, no exuviation had taken 

 place during the night. The latter was the animal, 

 clothed in its new garb, and close beside it lay its 

 former self, now an empty shell." 



The old shell is always found apparently quite 

 entire all the accessories and minutest parts in their 

 places bristles, antennae, eyes, all exactly resemble 

 the living and emancipated crab. And yet, when we 

 consider the amazing complexity of structure pre- 

 sented by the individual portions of the cast-off 

 skeleton, the joints and levers of the various limbs, 

 the numerous jaws, the stony teeth, the innumerable 

 facets of the compound eyes, and reflect upon the 

 difficulties attending the reconstruction of organs so 

 admirable and so delicate, few natural phenomena 



