31^8 Sir John Graham Dalyell, Bart., on 



wounds, — when I thought the new animal to be produced 

 might bediscovered lying with the limbs folded over thebreast. 



Another small crab, I, having lost five limbs, including one 

 of the claws, was diligently preserved. As reproduction is 

 first announced by a papilla rising from the remaining stump 

 in the mutilation of fleshy animals, I watched the several 

 stumps here preserved, without adverting to the improbability 

 of the same process when there was a casement of shell ; yet 

 I was so much influenced by what I had heard and read, that 

 I began at length to believe papillae actually perceptible ; but 

 in due time the illusion was dispelled by the appearance of 

 the new animal with all its ten limbs perfect, on exuviation. 

 No regenerating limb ever protrudes from the vacant stump. 

 Under all these circumstances, it is evident that the new sub- 

 ject — the shell and the animal — to be produced on exuviation, 

 must be concentrated within the smallest possible bounds, 

 lying with limbs crossed over the breast in the original shell, 

 which sunders or gapes between the hind pair of limbs, to 

 allow its exit when mature. 



Precisely the number of defective organs is presented by 

 exuviation along with the rest. A specimen of the Cancer 

 (or Fortunus) pusilhis^ whose limbs expanded two inches be- 

 tween the opposite extremities, had lost both the claws. From 

 this defect it fed itself with difficulty, for the claws of all 

 crabs, lobsters, and such animals are employed just as the 

 human hands. Both claws however appeared perfect in the 

 new animal introduced on exuviation. The same occurred 

 where only one pincer of the forceps of a claw was defective. 

 Taking everything in view, therefore, the whole parts con- 

 stituting the entire animal must be produced or reproduced 

 within the original or subsisting shell ; but generated or re- 

 generated. The time and mode whereby this is efl^ected, I 

 must leave more skilful physiologists to determine. 



The course of exuviation of the lobster tribe may be conve- 

 niently followed in the Crangon or shrimp, which is easily kept 

 and fed, and becomes very tame ; also the process is frequent. 

 The integument separates entire, and is almost colourless. 



The Cancer Bernhardus, the Soldier or Hermit Crab, is in- 

 termediate between the Cancer and Astacus. As only the 



