. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ELECTROLYTES IN PHASCOLOSOMA MUSCLE 449 The calculations of cellular potassium concentrations are calcula- tions based on the assumption that chloride does not penetrate the living cells. That is, cellular potassium concentration figures really represent the amount of potassium present in excess of chloride and presumably occupying space not penetrated by chloride. The mechanism for partitioning the elements in this fashion may or may not be the cell membrane but whatever it is, it has the interesting result that " cell
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ELECTROLYTES IN PHASCOLOSOMA MUSCLE 449 The calculations of cellular potassium concentrations are calcula- tions based on the assumption that chloride does not penetrate the living cells. That is, cellular potassium concentration figures really represent the amount of potassium present in excess of chloride and presumably occupying space not penetrated by chloride. The mechanism for partitioning the elements in this fashion may or may not be the cell membrane but whatever it is, it has the interesting result that " cell space " remains almost constant in spite of the fact that the muscle swells to almost double its original size. This fact is brought out clearly by the figures given in Table II. These figures are calculated from data read from the smoothed-out curves of Fig. 2. Cell size (volume of muscle not containing chloride) is calculated by multiplying the final relative wreight (initial weight = = 100) by the cell space (1 -Cli/Clo). From the figures shown it is apparent that these muscles can increase in weight by as much as 40 per cent and more than double the chloride space without any appreciable change in the calculated cell volume. It would seem rather doubtful that this actually means a constant cell size. A more liberal and probably more correct inter- pretation of the results would be that the protoplasm, due to its whole chemical and physical structure, represents non-solvent space as far as chloride is concerned. Permeability might be a factor in this but modified Donnan equilibria or other chemical equilibria must also be important. This interpretation probably holds also for Thyone muscles but is not needed so obviously since those tissues do not swell to any great extent in solutions of high potassium concentration. The calcium balance in the tissue was studied by methods similar to those used for potassium, except that dilutions were made with calcium chloride solut
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
