. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. e f g h FIG. 8. Diagrams illustrating the formation and " closure " of the blas- topore in Hemidactylium. No attempt is made to indicate exact relation of blastopore to egg equator. Margin of neural plate indicated by broken lines, a, early crescent blastopore; b, later crescent blastopore (from an- other egg) ; c, blastopore of b about 24 hours later; d, blastopore about n hours later than in c; c, later blastopore from another egg; /, blastopore of c about 9 hours later; g, smaller blastopore from another egg; h,
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. e f g h FIG. 8. Diagrams illustrating the formation and " closure " of the blas- topore in Hemidactylium. No attempt is made to indicate exact relation of blastopore to egg equator. Margin of neural plate indicated by broken lines, a, early crescent blastopore; b, later crescent blastopore (from an- other egg) ; c, blastopore of b about 24 hours later; d, blastopore about n hours later than in c; c, later blastopore from another egg; /, blastopore of c about 9 hours later; g, smaller blastopore from another egg; h, blastopore of g 10 hours later, reduced to short vertical slit which persists as anus. at its lateral margins (Fig. 8, &) until it assumes the form of a half circumference; sometimes it may become more extensive, as in Fig. 8, c, but in no case was the line of invagination or over- growth observed to become a complete circle surrounding a yolk plug. Following its period of greatest ventral extent the blas- topore shortens and assumes the form of a crescent with laterally directed margins (Fig. 8, d} ; by further narrowing and elevation of its lateral portions it assumes the form shown in Fig. 8, e, and finally the form of an inverted crescent (Fig. 8, /). As the neural folds close the blastopore gradually shortens (Fig. 8, g). 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
