. Comparative zoology, structural and systematic : for use in schools and colleges. Zoology; Anatomy, Comparative; Physiology, Comparative. PROTOZOA. 243. Fig. 1ST.—A Compound Monad (Uvella), X 1000. Class IV.—Infusoria. This unassorted group of living particles derived its name from the fact that they were first discovered in veg- etable infusions. Every drop of a stagnant pool is crowded with them. They are all single and microscopic, yet of various sizes, the difference between the small- est and largest being greater than the difference between a Mouse and an Elephant. Some are fixed (as V
. Comparative zoology, structural and systematic : for use in schools and colleges. Zoology; Anatomy, Comparative; Physiology, Comparative. PROTOZOA. 243. Fig. 1ST.—A Compound Monad (Uvella), X 1000. Class IV.—Infusoria. This unassorted group of living particles derived its name from the fact that they were first discovered in veg- etable infusions. Every drop of a stagnant pool is crowded with them. They are all single and microscopic, yet of various sizes, the difference between the small- est and largest being greater than the difference between a Mouse and an Elephant. Some are fixed (as Vorticella), but the majority are free, and constantly in motion, propelled by countless cilia, as a galley by its oars. The delicate body consists of two layers of sarcode (there are no cellular tissues, but the whole body represents a single cell), covered by a membrane, or skin, having one or two contractile cavi- ties, and a nucleus. Food-granules can often be seen. On one side is a slight depression, or " mouth," leading to a short, funnel-shaped throat. A mouth and a rudimentary digestive cavity are among the distinctive features of these Protozoans. Some have a pigment-speck —the simplest sense organ—and in the stem of Vorticella the first rudiments of muscle may be found. They multiply so rapidly (chiefly by self-division), that a Paramecium, the most common form, may become the parent of 1,364,000 in forty-two days. There are two main groups : Flagellata, or Monads, provided with one or two flagella, or long, bristle-like cilia; and Ciliata, which are furnished with numerous vibratile Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Orton, James, 1830-1877; Birge, E. A. (Edward Asahel), 1851-1950. New York : Harper & Bros.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1883
