. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FIGURE 2. Microphotographs of Clypcastcr larvae with oil drops injected into the blasto- coels. A. Early stage. Oil droplet is caught by the pseudopodia of the primary mesenchyme cells. B. Intermediate stage. The oil is picked up by the pseudopodia of the secondary mesen- chyme cells also. C, D. Later stages. As the pull by the secondary mesenchyme cells is stronger, the oil is removed from the primary mesenchyme cells and is drawn toward the archenteric tip. EFFECTS OF EXPERIMENTAL INCREASE OF THE BLASTOCOELIC VOLUME If the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FIGURE 2. Microphotographs of Clypcastcr larvae with oil drops injected into the blasto- coels. A. Early stage. Oil droplet is caught by the pseudopodia of the primary mesenchyme cells. B. Intermediate stage. The oil is picked up by the pseudopodia of the secondary mesen- chyme cells also. C, D. Later stages. As the pull by the secondary mesenchyme cells is stronger, the oil is removed from the primary mesenchyme cells and is drawn toward the archenteric tip. EFFECTS OF EXPERIMENTAL INCREASE OF THE BLASTOCOELIC VOLUME If the tip of the archenteron is actually being pulled up toward the animal pole by pseudopodia which have anchored themselves on the blastular wall, the pulling force will be increased if the blastocoelic volume is increased. This increased pull, in turn, would stretch the archenteron making it longer. Moore (1939, 1940) and Dan (1952) have reported that since the sea urchin blastular wall loses permea- bility to sucrose molecules after the tenth cleavage cycle (, at the time of hatch- ing), if larvae cultured in a sucrose-containing medium are transferred to pure sea water after hatching, they become considerably inflated as the result of an abnor- mally high internal osmotic pressure developed by the sucrose molecules entrapped in the blastocoel. Repetition of the sugar procedure on Clypeaster japonicus and Mespilia globulus gives not only a confirmatory result concerning the above expectation but it further. 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. : Marin
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
