But what was remarkable, the animal now had only the two large claws, the other eight limbs were deficient.  ’Resting on its breast as it was, I did not at first discover the fact, that the creature presented a strange and very uncouth aspect.  However, it fed readily, and proved very tame, though helpless; often falling on its back, and not being able to recover itself from the deficiency of its limbs.  I preserved this mutilated object with uncommon care, watching it almost incessantly day and night:  expecting another exuviation which might be attended with interesting consequences, I felt much anxiety for its survivance.  My solicitude was not vain.  After the defective shell had subsisted eighty-six days, its tenant meantime feeding readily, the desired event took place in a new exuviation on 23d June.  On this occasion a new animal came forth, and in the highest perfection, quite entire and symmetrical, with all the ten limbs peculiar to its race, and of the purest and most beautiful white.  I could not contemplate such a specimen of nature’s energies restoring perfection, and through a process so extraordinary, without admiration.  Something yet remained to be established:  was this perfection permanent, or was it only temporary?  Like its precursor, this specimen was quite tame, healthy, and vigorous.  In 102 days it underwent exuviation, when it appeared again, perfect as before, with a shell of snowy white, and a little red speckling on the limbs.  Finally, its shell having subsisted 189 days, was succeeded by another of equal beauty and perfection, the speckling on the legs somewhat increased.  As all the shells had gradually augmented, so was this larger than the others.  The extended limbs would have occupied a circle of four inches diameter.  About a month after this exuviation the animal perished accidentally, having been two years and eight months under examination.  It was an interesting specimen, extremely tame and tranquil, always coming to the side of the vessel as I approached, and holding up its little claws as if supplicating food.’

The shrimp when in confinement becomes very tame, and readily exuviates.  The process is frequent, the integument separates entire, and is almost colourless.  In female crustaceans the roe is placed outside the shell to which it adheres.  During the period of such adherence, the female crab, so far as observation goes, does not change its shell—­a marked provision of nature to preserve the spawn.

We may remark that other classes of animals exuviate in a similar manner to the crustaceans.  Thus serpents throw off in entire masses their scaly coverings, even a slough from the eyes; and various insects in their larva state are continually throwing off and renewing their skins.

FOOTNOTES: 

[2] Report of British Association, 1851.  Pp. 120-122.

THE AYAH.