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. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. MODIFICATIONS IN THE SAND DOLLAR 483 From these experiments it was shown that when the eggs of D. excentricus were exposed to a combined solution of cobalt and selenite (M/1,600 CoCl2-M/1,600 Na2SeO3) they differentiated according to a pattern of radial symmetry very much as if they had been exposed to single solutions of double strength of either agent. That is, while M/1,600 cobalt alone caused 10 per cent radial and M/1,600 selenite alone caused 25 per cent radial, together they caused 100 per cent radial (approxi- mately
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. MODIFICATIONS IN THE SAND DOLLAR 483 From these experiments it was shown that when the eggs of D. excentricus were exposed to a combined solution of cobalt and selenite (M/1,600 CoCl2-M/1,600 Na2SeO3) they differentiated according to a pattern of radial symmetry very much as if they had been exposed to single solutions of double strength of either agent. That is, while M/1,600 cobalt alone caused 10 per cent radial and M/1,600 selenite alone caused 25 per cent radial, together they caused 100 per cent radial (approxi- mately 100 per cent radial forms are caused by M/800 of either agent). In the case of polar elongation the combined solution gave a considerably higher percentage than did the single solutions (M/1,600 CoCl, or M/1,600 Na2SeO3) but not as high as single solutions of double strength. Exogastrulation was highest in the cobalt,. 8. 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