. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. mm. mm FIGURE 1. Late embryonic stages of Laeonereis cnh'cri: (A) forty-eight hour, spherical, setigerous embryo in lateral view; (B) fifty-two hour, elongating embryo in ventral view. The macromeres are yellow to amber in color and contain most of the yolk. They are unequal in size, the anterior pair being smaller than the posterior pair and the left member of the posterior pair being somewhat larger than the right one. Four macromeres usually occur, but in exceptional cases five or six may form. Embryos with more t
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. mm. mm FIGURE 1. Late embryonic stages of Laeonereis cnh'cri: (A) forty-eight hour, spherical, setigerous embryo in lateral view; (B) fifty-two hour, elongating embryo in ventral view. The macromeres are yellow to amber in color and contain most of the yolk. They are unequal in size, the anterior pair being smaller than the posterior pair and the left member of the posterior pair being somewhat larger than the right one. Four macromeres usually occur, but in exceptional cases five or six may form. Embryos with more than four macromeres appear to develop normally. The micromeres com- pletely overgrow the macromeres in typical epibolic gastrulation within 24 to 30 hours. Further development leads directly to a spherical, setigerous embryo by 48 hours (Fig. 1A). The embryo lacks cilia and does not rotate, but does twitch sporadically. The fertilization membrane and the surface of the body are in loose contact. With each twitch, the body surface is deformed and slightly removed in places from the encompassing fertilization 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
