. A manual of zoology. Zoology. I. RHIZOPODA: HELIOZOA 173 a single (sometimes several) nucleus (w), which is vesicular, and contains either one large or several smaller nucleoli. A contractile vacuole is usually present. Reproduction occurs by binary or multiple division (fig. 120), and encystment has been observed, the protoplasm dividing into many hundred small amoeba;, a phenomenon always connected wdth fertilization processes (au- togamy?). Most Lobosa occur in fresh water; A. terricola in moist earth. There are also parasites like A. coli, rare in colder climates, frequently observed in
. A manual of zoology. Zoology. I. RHIZOPODA: HELIOZOA 173 a single (sometimes several) nucleus (w), which is vesicular, and contains either one large or several smaller nucleoli. A contractile vacuole is usually present. Reproduction occurs by binary or multiple division (fig. 120), and encystment has been observed, the protoplasm dividing into many hundred small amoeba;, a phenomenon always connected wdth fertilization processes (au- togamy?). Most Lobosa occur in fresh water; A. terricola in moist earth. There are also parasites like A. coli, rare in colder climates, frequently observed in the tropics. According to recent researches two forms have been included under the name A. coli, one innocuous, Entamceba coli, and another (possibly several) pathogenic forms, inchiding E. Iiistolytica, which appears in enormous numbers in abscesses of the liver and ulcers of the colon of men ill with tropical dysentery For the first of these it is certain, for the other probable, that infection is caused by encysted forms, which arise as a consequence of fertilization and are passed out with the Fig. 120.—Amccha polypodia in division (after F. E. Scliulze). cv, contractile vacuole; el^, ectosarc; en, en- tosarc; n, nucleus. Order III. Heliozoa, Sun Animalcules. The Heliozoa owe their name to the shape of the body, with the pseudopodia arranged like rays. In each pseudopodium is a firm axial thread, forming a. 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 Hertwig, Richard, 1850-1937; Kingsley, J. S. (John Sterling), 1854-1929, ed. and tr. New York, H. Holt
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1912
