United States or Azerbaijan ? Vote for the TOP Country of the Week !
This was the same animal, which had performed exuviation, and extricated itself from the old shell during the night. The resemblance between both forms was complete everything was the same, even the white limb was seen in both.
The third shell came on uniformly green, the white spots being entirely obliterated. On the fourth exuviation, the limbs expanded two inches and a half. From the long slender form of the limbs of crustacea, they are very liable to mutilation. Crabs are also a very pugnacious family, and in their battles limbs are often snapped off.
It appears from Sir John's observations that crustaceans begin to throw off their shells at a very early period of their life, even in that embryo state in which they first appear after having left the egg, and before they have yet assumed the real form of their mature state. During every successive exuviation in this embryo state, they assume more and more of their perfect and established form.
Now, as this shelly integument envelops them from their earliest youth, and as it does not expand and grow, the natural growth of the soft body beneath would be entirely prevented did not nature supply a remedy of a very curious kind the exuviation, or periodical throwing off of the external crust, and the formation of a larger shell-covering fitted for the increasing growth of the animal.
Society, in all its developments, undergoes the process of exuviation. These old forms which it successively throws off, have all been once vitally united with it have severally served as the protective envelopes within which a higher humanity was being evolved.
In England and America, religious persons perceive with dismay that the intellectual basis of faith has been undermined by the spirit of the age. They prepare for the approaching disaster in the best manner they can. The most serious trial through which society can pass is encountered in the exuviation of its religious restraints.
Its first exuviation ensued on 8th November, the second on the 30th of April following, and the shell then produced subsisted till 12th September, when another exuviation took place, introducing a new shell of such transparent white that the interior almost shone through it. All the shells were white, and increased somewhat in size successively.
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.
While the crab is young and rapidly growing, frequent exuviations take place at short intervals, from three to five times in the course of one year. Previous to the change, the animal almost ceases to feed, and becomes rather inactive; the proper time having at length arrived, exuviation is effected in the course of a few hours, body and limbs being alike relieved from their hard covering.
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.
Word Of The Day