. A manual of zoology. Zoology. IV. CILIATA 193. Fig. 151.—Conjugation in ParamcBcium. k, macronucleus; k/?, micronudeus; 0, cyto- stomes. I. Changes of micronudeus; left siclvle stage, right spindle stage. II. Second division of micronudeus; into primary spindles (i, 5) and secondary spindles (2, 3, 4; 6, 7, 8). III. Degeneration of secondary spindles (2, 3, 4; 6, 7, 8); di\'ision of primary spindle nto male (i"f, ^m) and female spindles (iiti', 5^). IV. Exchange of male spindles nearly complete (fertilization), one end still in the parent animal, the other united with the female spindle
. A manual of zoology. Zoology. IV. CILIATA 193. Fig. 151.—Conjugation in ParamcBcium. k, macronucleus; k/?, micronudeus; 0, cyto- stomes. I. Changes of micronudeus; left siclvle stage, right spindle stage. II. Second division of micronudeus; into primary spindles (i, 5) and secondary spindles (2, 3, 4; 6, 7, 8). III. Degeneration of secondary spindles (2, 3, 4; 6, 7, 8); di\'ision of primary spindle nto male (i"f, ^m) and female spindles (iiti', 5^). IV. Exchange of male spindles nearly complete (fertilization), one end still in the parent animal, the other united with the female spindle, im, with 5TO and ^m with iw; macronucleus broken up. V. The cleavage spindle t formed by male and female »pindles di"viding into the secondary cleavage spindles t', t". VI. VII. End of conjugation. The secondary cleavage spindle dividing into the anlage of the new micronudeus (n^'), and that of the new micronudeus, pt (placenta). The fragments of the old macronucleus begin to degenerate. Since P. caudatum shows the earlier and P. aurelia the later stages better, these forms have been used, P. caudatum for I-III, P. aurelia for the rest. The differences consist in the existence of one micronudeus in P. caudatum, two in P. aurelia and that in the latter the nuclear degeneration begins in I. 13. 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
