structure - we can hardly conceive any other form either smaller or simpler-we are in a posi tion to state that the radical or primitive attributes of life, those characteristics by which it is distinguished from mere physical existence, are the capacity to select, transform and vitalize matter, and the capability to extend the dimensions of its own structures, and to reproduce its kind. change their position under especial circumstan- | As, therefore, these microscopically minute bladces; but when they do so, they move, as a whole, ders must be assumed to be the radical, or, to use without bending or altering their shapes, as the a synonymous term, the primitive form of living amaba has been described to do. It may also be added, that when vegetable cells travel, they never avoid obstacles that chance to be in their way they go on in straight lines, until they knock against some rock ahead, and they then stick there, without any attempt to extricate themselves from the difficulty. Animalcules, on the other hand, steer themselves adroitly round whatever chances to lie across their path. Animalcules are locomotive by design and through intent, but vegetable cells are never locomotive excepting from some extraneous or accidental influence. But we have yet to make good our assumption, that little living vesicles are radical members of society as well as the radical forms of life. This we shall now be able, in a very few Some very curious forms occur among the ac- words, to do. If we leave placid pools and tive animalcules, which, at the first glance, ap- stagnant ditches, and attack with our " prying" pear to be wide departures from the simple vesi-instruments the fastnesses of vitality-such nocular type of being instanced in the amæba, but ble structures as the trees of the forest and the which are really, after all, very slight deviations beasts of the plain-we shall find that they, too. from that condition. These animalcules look are but heaps of microscopic vesicles: we shall like bags with open mouths, instead of being see cells in the green leaf, in the solid wood, in closed bladders, and they take their food into the coursing blood. Man himself is but a pile their interior cavities by an apparent act of of vesicles. By the microscope, we detect eviswallowing, and retain it there until digested. In dence of their presence in bone, in flesh, in fat, these cases, however, the interior cavity is merely in veins, in skin, in hair, and, in short, in every a fold or pouch of the general surface thrust in-organ and in every piece of apparatus of his wards. If, when the amaba has folded its mem- wonderful system. The fact is merely, that in braneous wall round some morsel of food, it these complex productions of life, the successive were permanently to retain the form it had thus generations of vesicles that are formed out of taken, leaving an open mouth where the inward the primary ones, are attached together to build folding occured, it would exactly represent the up the several parts of the connected frame, instate of the bag-animalcules. Some of those stead of being scattered abroad as a swarm of creatures, indeed, have been turned inside out-independent creatures, each being then altered the skin being made to take the place of stom-in character and form subsequently to its first ach, and the stomach of skin, and no harm has construction, to render it suitable for some speresulted to their economy. cial purpose in the organization, or for some parWe have now shown that the little vesicular ticular position in the fabric. All plants, all anibodies we have been contemplating are living mals, and even man himself, are made up of structures they prove themselves to be living multitudes of little vesicles; and of these vesiby the performance of five distinct and wonder- cles each one is a living structure, capable of seful operations, which dead matter can never ac- lecting, appropriating, and vitalizing its food. complish they select certain nutritious princi- and of growing and reproducing its kind; hence ples that are suitable for employment or build- there is in all these creatures a vesicular life, ing purposes; they transform these principles which sustains the life of the individual, and mininto membrane like that of which they are them-isters to it, so to speak. This vesicular life, is selves composed; they appropriate this membrane to the enlargement of their own bodies; they vitalise it at the same time-that is, they enable each addition made forthwith to take upon itself the same selecting, transforming, and vitalizing functions; and they multiply their forms by falling to pieces, and contributing cach piece as the foundation of a new growing organism, capable of becoming in every respect like to themselves. All these five things every little diatom, every amæba, every individual of an allied host of creatures, is able of itself to perform. [ AUTUMNAL SONNET. Now Autumn's fire burns slowly along the woods, Or grim wide wave; and now the power is felt called organic life, because it carries on all the Than any joy indulgent summer dealt. LITTELL'S LIVING AGE-No. 537.-2 SEPT., 1854. By menials beckoned to a lowly chair, Still true to art, because to nature true. V. THE crowning apple speaks the finished feast-Changes the various scene, excursive, new, Silenced the hum of conversation round;- |