172 Exuviation in Shrimps and Lobsters. 



left by the creature when it made its escape : — for escape it did, 

 through an aperture too narrow to have allowed it to pass if its new 

 covering had possessed a very moderate degree of firmness — to the 

 no small annoyance of the fisherman, who had calculated on the pos- 

 session of a prize somewhat above the ordinary magnitude. I can- 

 not find that any extraordinary actions or contortions have been ob- 

 served in the lobster, when engaged in delivering itself from its 

 trammels, or that the time is prolonged, as is the case with the cray- 

 fish : circumstances which are easily accounted for by an examina- 

 tion of the crust ; and it is certain that when delivered it possesses 

 great activity in effecting its escape, and that neither the prawn nor 

 the lobster devour, as has been supposed, any portion of the old 

 shell. 



In the specimen referred to, the case of the antennae and palpi, 

 was perfect to their minutest extremities ; the stalk also, and tran- 

 sparent covering of the eyes, were uninjured, but the former was at- 

 tached on its inferior portion only, the superior half hanging loose, 

 so that it would soon have fallen away in the agitation of the sea. 

 The segments and joints of the posterior portion of the body, with 

 the caudal plates, were all joined together, but without any inter- 

 vening membrane ; and the inferior parts from beneath the snout, 

 including the jaws and footjaws, chelsedlegs, with the sternal plate, 

 oesophagus and internal coat of the stomach, formed one connected 

 portion, with no farther separation than arises from the absence of 

 every portion of membrane. The whole of these inferior por- 

 tions was drawn very considerably within the carapace ; and it was 

 the latter section of the surface only that showed a mark of the man- 

 ner in which the animal had delivered itself from its case ; and this 

 it did. in a way not to be mistaken. Through the middle of this 

 space, ran a line as straight as if it had been cut with a knife, and 

 evidently formed by a natural process of separation : for it even pro- 

 ceeded through the centre of the snout, to the terminal pointed pro- 

 cess, at the root of which it turned off on the right side ; so that the 

 least effort of the animal was sufficient to afford it a passage. 



The observation here made on a very perfect specimen that came 

 into my possession by great accident, has been further confirmed by 

 a careful examination, both of the living lobster, in which an obscure 

 line is perceptible, where the natural separation takes place ; and 

 also of a specimen of small size, in which the sloughing or na- 

 tural process of division had only begun. In the.latter case a deep 

 channel had been formed on the external part, nearly half through 

 the carapace ; while the internal portion still remained firm ; but 



