. The cell in development and inheritance. Cells; Cells. 3o8 THEORIES OF INHERITANCE AND DEVELOPMENT meres of sea-urchin eggs separated by shaking to pieces the two- cell and four-cell stages. Blastoraeres thus isolated segment as if still forming part of an entire larva, and give rise to a half- (or quar- ter-) blastula (Fig. 132). The opening soon closes, however, to form a. Fig. 134. — Dwarf and double embryos of Amphioxus. A. Isolated blastomere of the 2-celI stage segmenting like an entire egg (cf. Fig, 123,/)). B. Twin gastrulas from a single egg. C. Double cleavage resulting from the pa
. The cell in development and inheritance. Cells; Cells. 3o8 THEORIES OF INHERITANCE AND DEVELOPMENT meres of sea-urchin eggs separated by shaking to pieces the two- cell and four-cell stages. Blastoraeres thus isolated segment as if still forming part of an entire larva, and give rise to a half- (or quar- ter-) blastula (Fig. 132). The opening soon closes, however, to form a. Fig. 134. — Dwarf and double embryos of Amphioxus. A. Isolated blastomere of the 2-celI stage segmenting like an entire egg (cf. Fig, 123,/)). B. Twin gastrulas from a single egg. C. Double cleavage resulting from the partial separation, by shaking, of the blastomeres of the 2-cell stage. D. E. F. Double gastrulas arising from such forms as the last. small complete blastula, and the resulting gastrula and Pluteus larva is a perfectly formed dwarf of only half (or quarter) the normal size. Incompletely separated blastomeres gave rise to double embryos like the Siamese twins. Shortly afterwards the writer obtained similar result in the case of Amphioxus, but here tJie isolated blastomere scg-. 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 : The Macmillan company
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectcells, bookyear1896
