The cell in development and inheritance . Fig. 179. — Outline of unsegmented squids egg, to show bilaterality. [Watase.]A. From right side. B. From posterior antero-posterior axis ; d-v. dorso-ventral axis ; /. left side ; r. right side. disentangling the complicated factors of development through a com-parative study of the different forms. {c) Other Promorphological CJiaracters of the Ovum. — Besides thepolarity of the ovum, which is the most constant and clearly markedof its promorphological features,we are often able to discover othercharacters that more or less clearly foresha
The cell in development and inheritance . Fig. 179. — Outline of unsegmented squids egg, to show bilaterality. [Watase.]A. From right side. B. From posterior antero-posterior axis ; d-v. dorso-ventral axis ; /. left side ; r. right side. disentangling the complicated factors of development through a com-parative study of the different forms. {c) Other Promorphological CJiaracters of the Ovum. — Besides thepolarity of the ovum, which is the most constant and clearly markedof its promorphological features,we are often able to discover othercharacters that more or less clearly foreshadow the later develop-ment. One of the most interesting and clearly marked of these isthe bilateral symmetry of the ovum in bilateral animals, which issometimes so clearly marked that the exact position of the embryomay be predicted in the unfertilized tgg, sometimes even before it islaid. This is the case, for example, in the cephalopod e^gg, as shownby Watase (Fig. 179). Here the form of the new-laid &gg, beforecleavage begins,
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectcells, bookyear1902
