. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FERTILIZATION REACTION IN ECHINARACHNIUS PARMA. Immediately on insemination, sperm pierce the jelly hull, reaching the vitellus with rapid spiral movements; the moment the tip of the sperm touches the cortex of the vitellus all move- ments cease, the head and tail in a straight line at right angles to a tangent of the egg surface. Penetration follows as an activity of the egg; the spermatozoon does not bore its way in — the egg pulls it After the head has disappeared within the cortex, mem- brane elevation begins. After
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FERTILIZATION REACTION IN ECHINARACHNIUS PARMA. Immediately on insemination, sperm pierce the jelly hull, reaching the vitellus with rapid spiral movements; the moment the tip of the sperm touches the cortex of the vitellus all move- ments cease, the head and tail in a straight line at right angles to a tangent of the egg surface. Penetration follows as an activity of the egg; the spermatozoon does not bore its way in — the egg pulls it After the head has disappeared within the cortex, mem- brane elevation begins. After the sperm head has completely dis- appeared within the egg, the cortex reacts to penetration by pushing out a blister at the site of sperm entry (Fig. 2). This blister, which is not optically empty but contains minute drops that wander across this newly formed perivitelline space, may push off at once to a. ..«- FIG. Freshly shed egg. Its pigmented jelly is as yet un- swollen by the sea 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
