A very simple and ingenious plan of demonstrating the uses of the cilia in sweeping food-particles into the mouths of the animalcules, was devised by Ehrenberg, the great German naturalist. This plan consists in strewing in the water in which the animalcules exist, some fragments of coloured matter, such as indigo or carmine, in a very fine state of division. These coloured particles can readily be traced in their movements, and accordingly we see them tossed about and whirled about by the ciliary currents, and finally swept into the mouths of the animalcules, which appear always to be on the outlook, if one may so term it, for nutritive matter. Sometimes when we may be unable to see the cilia themselves, on account of the delicate structure, we may assure ourselves of their presence by noting the currents they create.
The structure of the bell-animalcules is of very simple and primitive kind. The body consists of a mass of soft protoplasm—as the substance of the lower animals and plants is named; but this matter is capable of itself of constituting a distinct and complete animal form, and of making up for its want of structure by a literally amazing fertility of functions. Thus it can digest food; for in the bell-animalcules and their neighbours, the food-particles swept into the mouth are dissolved amid the soft matter of the body in which they are imbedded. Although the animalcules possess no digestive system, the protoplasm of the body serves them in lieu of that apparently necessary apparatus, and prepares and elaborates the food for nourishing the body. Then we have seen that the animalcules contract when irritated or alarmed. A tap on the slide of glass on which they are placed for microscopic examination, initiates a literal reign of terror in the miniature state; for each animalcule shrinks up as if literally alarmed at the unwonted innovation in its existence. This proceeding suggests forcibly to us that they are sensitive—if not in the sense in which higher animals exhibit sensation, at least in much the same degree and fashion as a sensitive plant. And where sensation exists, analogy would lead us to believe that some form of apparatus resembling or corresponding to nerves exercising the function of feeling, must be developed in the animalcules. Yet the closest scrutiny of the bell-animalcules, as well as of many much higher forms, fails to detect any traces of a nervous system. And hence naturalists fall back upon the supposition that this curious protoplasm or body-substance of these and other lower animals and plants, possesses the power of receiving and conveying impressions; just as in the absence of a stomach, it can digest food.
The last feature in the organisation and history of the bell-animalcules that we may allude to in the present instance is that of their development. If we watch the entire life-history of these animalcules, we shall observe the bell-shaped heads of various members of the colony to become broadened, and to increase disproportionately in size. Soon a groove or division appears in this enlarged head; and as time passes, the head appears to divide into two parts or halves, which for a time are borne by the one stalk. This state of matters, however, does not continue; and shortly one of the halves breaks away from the stalk, leaving the other to represent the head of the animalcule. This wandering half or head is now seen to be provided at each end with cilia, and by means of these filaments swims freely throughout the surrounding water. After a time, however, it settles down, develops a stalk from what was originally its mouth extremity; whilst the opposite or lower extremity with its fringe of cilia comes to represent the mouth of the new animalcule. We thus note that new bell-animalcules may be produced by the division of the original body into two halves. They also increase by a process of budding. New buds grow out from the body near the attachment of the stalk; these buds in due time appearing as young Vorticellæ, which detach themselves from their parent and seek a lodgment of their own.
These briefly sketched details may serve to interest readers in a comparatively unknown field of observation, accessible to every one who cares to know something of one of the many life-histories with which our universe teems, but which from their very plenty are seldom thought of or recognised. And the present subject is also not uninteresting if we regard it in the light of a corrective to those too commonly received notions, usually fostered by ignorance of our surroundings, that there is nothing worth attention in the universe but humanity and human affairs.
[ADVICE TO YOUNG WOMEN.]
In marrying make your own match: do not marry a man to get rid of him or to save him. The man who would go to destruction without you would as likely go with you, and perhaps bring you along. Do not marry in haste, lest you repent at last. Do not let aunts, fathers, or mothers sell you for money or position into bondage, tears, and life-long misery, which you alone must endure. Do not place yourself habitually in the society of any suitor until you have decided the question of marriage; human wills are weak, and people often become bewildered, and do not know their error until it is too late. Get away from their influence, settle your head, and make up your mind alone. A promise may be made in a moment of sympathy, or even half-delirious ecstasy, which may have to be redeemed through years of sorrow, toil, and pain. Do not trust your happiness to the keeping of one who has no heart, no health. Beware of insane blood, and those who use ardent spirits; shun the man who ever gets intoxicated. Do not rush thoughtlessly, hastily, into wedded life, contrary to the counsels of your friends. Love can wait; that which cannot wait is something of a very different character.—Newspaper paragraph.
[LINES TO THE MEMORY OF THOMAS TYRIE,]
A YOUNG EDINBURGH POET OF GREAT PROMISE.