On the 11th of July, the upper part. of an actinia was cut off: new limbs began to shoot out on the 21st, and two rows of them were seen on the 25th. The colour ing of the tentacula was faintly renewed on the 1 1 th of August, and soon afterwards it would scarcely be known that an operation had been performed. Here it may be observed, that all reproduced parts are of a pale light colour, which darkens with age.
In another actinia, cut asunder on the 7th of August, the third row of tentacula was visible on the 9th of September, and a fourth on the 19th. On the 3d of October it began to eat, and soon after became a per fect animal.
The period required for complete reproduction is extremely various, and chiefly dependent on the frequent renewal of sea water, and the temperature of the atmos phere. In favourable conditions, the tentacula are some times regenerated in a few days. A young anemone, cut asunder on the 16th of June, had the upper half re produced on the 30th. One, as thick as the arm, being divided on the 18th of October, put forth new limbs be fore the end of the month ; but it did not begin to feed until the 10th of December, at which time its mouth was hardly formed.
Similar to what succeeds in other animals enjoying the same prerogative, if the part reproduced is severed from the actinia, a new reproduction will ensue. We know not how often this experiment may be repeated : But it is established by the concurring testimony of re putable authors, that several heads may be successively obtained, by .iecapitating certain species of snails ; and we apprehend, that the reproductive powers of actinic: are ample with theirs.
The course of nature is sometimes diversified in ac complishing the reproduction of horizontal sections. In one experiment, where an animal flower was cut asun der, the upper half, instead of acquiring a new base in place of that which was wanting, shot forth new tenta cula from its under part; and a monstrous animal, which fed at both ends, was thus produced.
The reproductive powers of the actinic: are not limit ed to horizontal sections only ; for one, cut perpendicu larly down the middle, will become two perfect and en tire animals ; so perfect, as to propagate after the repro duction has been completed, or while it is going on. Of this we have various instances, equally well ascertained as the preceding.
A large anemone, just taken out of the sea, was cut perpendicularly into four parts. It immediately dis
charged twelve young ones, which is not an uncommon occurrence however; for these animals, on suffering pain, frequently discharge their young. Besides the twelve at first produced, three of the quarters produced fourteen more, but the fourth none.
Although the perpendicular section succeeds in ob taining complete reproductions, it is more difficult to per form, and is accomplished with less certainty. Perhaps the vital powers are exposed to greater injury : we know indeed that merely cutting the base asunder is utterly destructive of some species of these animals. But the ultimate cause of the fact, notwithstanding we may daily behold it, is still involved in obscurity, and will remain so until we can obtain some definite idea of the chief residence of the vital principle. Many other animals evince similar peculiarities. The brain, the heart, the lungs, seem endowed with different degrees of vitality. The life of these organs, in some animals, seems dependent on each other ; and the slightest con tact with external substances will occasion instant death. But there are animals unquestionably which can ^urvive total privation of those we deem the most indispensible, for days, weeks, and even entire months.
Among the more unaccountable reproductions of the animal flower, are those arising from the shreds torn off its base. It frequently happens, that, in sudden contrac tions, all the surface is not detached with equal celerity. whence certain portions are separated and left behind, adhering to the substance where the animal flower was fixed : these become complete, like the parent animal.
On the first of October, an actinia, by a sudden con traction, lost a fragment in this manner, which formed an irregular segment of the circle formed by its base. In a few days, the fragment grew larger, and then re sembled the segment of a sphere. During a month, neither the mouth nor tentacula were visible ; but, on the 7th of November, they could be seen by means of a powerful magnifier, and were distinctly perceptible on the 16th. In the beginning of the subsequent January, this portion completely resembled the original actinia, in every thing excepting the number of tentacula. In another experiment, ten small shreds, cut with a knife from the ,bases of different sea alimonies, grew into as many perfect animals.