. The microscope; a simple handbook. Microscopes. THE MICROSCOPE AS A RECREATION 127. Fig. 115.—Difflugia. somewhat darker and harder material, is always present and is essential to life. What part it plays is unknown; it appears to be a kind of vital spark, and is called the Nucleus. The other organ is nothing more or less than a good-sized bubble, called the Vacuole. The Amoeba, the simplest form of animal that exists, is so colour- less and so transparent that every- thing going on in its interior is visible. Its structure can be imderstood at a glance, and start- ing from this simple form
. The microscope; a simple handbook. Microscopes. THE MICROSCOPE AS A RECREATION 127. Fig. 115.—Difflugia. somewhat darker and harder material, is always present and is essential to life. What part it plays is unknown; it appears to be a kind of vital spark, and is called the Nucleus. The other organ is nothing more or less than a good-sized bubble, called the Vacuole. The Amoeba, the simplest form of animal that exists, is so colour- less and so transparent that every- thing going on in its interior is visible. Its structure can be imderstood at a glance, and start- ing from this simple form we can find creatures varying from each other but slightly, which show step by step an almost com- plete series of stages of development up to elaborate organisms. For instance, there is one species of Amoeba which has one end of its body hardened into an unchanging shape—just one corner only around which some of the jeUy has hardened up at the edge, showing the commencement of the development of a covering, while the rest of the creature is exactly like its simpler brother, having, with the exception of this little corner, no fixed shape, but pouring about as before. The next shape is reached in the Difflugia. It is an Amoeba and possesses the same curious means of engulfing food; but when in the course of its meals it gets outside pieces of sand or similar indigestible material, it retains them, fixing them around the surface of its body until a cap is formed and only a small portion of the jeUy is left free. These particles are cemented together with some of the hardened jelly, and form a rough sheU in the shape of an egg with one end broken ofi. From this open end the creature flows in irregular projections of jelly to catch food, and crawls about carrying the shell on its back. It seems to have a power of selection as to the size and shape of the grains that will form a satisfactory shell, and, although there is not a perfect regularity in its construction, it is evide
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectmicroscopes, bookyear
