. The cell in development and inheritance. Cells. "V V Fig. 179. — Outline of unsegmented squid's egg, to show bilaterality. [WATASE.] A. From right side. B. From posterior aspect. a-p. antero-posterior axis; d-v. dorso-ventral axis; /. left side; /-. right side. disentangling the complicated factors of development through a com- parative study of the different forms. {c) OtJier ProinorpJwIogical Characters of the Ovum. — Besides the polarity of the ovum, which is the most constant and clearly marked of its promorphological features, we are often able to discover other characters that mor
. The cell in development and inheritance. Cells. "V V Fig. 179. — Outline of unsegmented squid's egg, to show bilaterality. [WATASE.] A. From right side. B. From posterior aspect. a-p. antero-posterior axis; d-v. dorso-ventral axis; /. left side; /-. right side. disentangling the complicated factors of development through a com- parative study of the different forms. {c) OtJier ProinorpJwIogical Characters of the Ovum. — Besides the polarity of the ovum, which is the most constant and clearly marked of its promorphological features, we are often able to discover other characters that more or less clearly foreshadow the later develop- ment. One of the most interesting and clearly marked of these is the bilateral symmetry of the ovum in bilateral animals, which is sometimes so clearly marked that the exact position of the embryo may be predicted in the unfertilized ^%^, sometimes even before it is laid. This is the case, for example, in the cephalopod &gg, as shown 'by Watase (Fig. 179). Here the form of the new-laid Q,^g, before cleavage begins, distinctly foreshadows that of the embryonic body, and forms as it were a mould in which the whole development is cast. Its general shape is that of a hen's t,gg slightly flattened on one side,. 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 Wilson, Edmund B. (Edmund Beecher), 1856-1939. New York, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcells, bookyear1911
