. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ACTIVATION BY BIVALENT CATIONS 269 There is a higher percentage of cleavage in shed eggs than in ovary eggs and a slightly higher percentage of cleavage in washed shed eggs than in shed eggs. Table III shows that when the unfertilized eggs of one individual are placed in solutions of CaCL in which the pHs vary from to , for from 5 to 9 hours, the percentage of cleavage is low below pH and is only slightly higher at pH while the highest percentage of cleavage takes place at about pH Cleavage takes place in
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ACTIVATION BY BIVALENT CATIONS 269 There is a higher percentage of cleavage in shed eggs than in ovary eggs and a slightly higher percentage of cleavage in washed shed eggs than in shed eggs. Table III shows that when the unfertilized eggs of one individual are placed in solutions of CaCL in which the pHs vary from to , for from 5 to 9 hours, the percentage of cleavage is low below pH and is only slightly higher at pH while the highest percentage of cleavage takes place at about pH Cleavage takes place in the short - 100 o 0> Rotio FIG. 3. Action on Arbacia eggs of isotonic solutions of some monovalent and bivalent cations singly and in various mixtures and proportions. K/Ca—average of fourteen experiments. Na/Ca—average of nine experiments. Li/Ca—average of eight experiments. Na/Mg—average of three experiments. est time at pH but the eggs soon undergo cytolysis. High alkalinity also seems to cause nuclear division without cytoplasmic cleavage in a large percentage of eggs. In many cases there is little and sometimes no cleavage in solutions of which the pH is about while there may be a high percentage of cleavage in solutions of which the pH is about Arbacia eggs are not activated by alkaline sea water. Effect of Mixtures of Calcium Chloride and Some Monovalent Ca- tions.—The result of experiments in which eggs were exposed to solu- tions of potassium, sodium or lithium and calcium chloride in various. 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. Wo
Size: 1789px × 1396px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
