. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SURFACE CHANGES IN ASCIDIAN FERTILIZATION 357. FIGURE 1. Phase contrast micrograph of a living unfertilized Ascidia malaca egg. fc = follicle cell; tc = test cell; vc = vitelline coat. 270X. FIGURE 2. Transmission electron micrograph (TEM) of envelopes of unfertilized egg. Arrows indi- cate coating of the outer vitelline coat; pm = plasma membrane. 2500X. FIGURE 3. Phase contrast micrograph of a living fertilized egg; test cells have migrated towards the vegetal hemisphere (arrows), vp = vegetal pole. 290X. FIGURE 4. TEM of
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SURFACE CHANGES IN ASCIDIAN FERTILIZATION 357. FIGURE 1. Phase contrast micrograph of a living unfertilized Ascidia malaca egg. fc = follicle cell; tc = test cell; vc = vitelline coat. 270X. FIGURE 2. Transmission electron micrograph (TEM) of envelopes of unfertilized egg. Arrows indi- cate coating of the outer vitelline coat; pm = plasma membrane. 2500X. FIGURE 3. Phase contrast micrograph of a living fertilized egg; test cells have migrated towards the vegetal hemisphere (arrows), vp = vegetal pole. 290X. FIGURE 4. TEM of a head of a fully differentiated spermatozoon from the sperm duct, m = mito- chondrion; n = nucleus. FIGURE 5. TEM of envelopes of a fertilized egg; spermatozoa are found in the vitelline coat (arrow- heads). 5000X. shaped, highly vacuolated hexagonally arranged cells; their convex basal region forms indentations in the vitelline coat, which are clearly seen when the latter is cut away (Fig. 11). The follicle cells touch one another only at their basal region, where the plasma membranes of adjacent cells seem to interdigitate, separated by narrow clefts. The clefts are the only means by which the sperm can reach the subjacent vitelline coat, where the "sperm reaction"—involving swelling, migration, and loss of the mi- tochondrion—occurs. In fact, many "remnants" of spermatozoa ( mitochondrion plus tail), and only a few intact ones, are found mainly in the cleft zone 3 minutes. 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. : Ma
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
