. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEA-SALTS ABOUT ARBACIA EGGS. 181 of eggs removes one third as much as in three. On the basis of these assumptions and the actual titrations, we can con- struct a curve showing the comparative amounts of chlorine which, under the conditions imagined, I of eggs would ab- stract from i of sea-water in one hour, if the rate of removal for that hour were constantly the rate deducible from the de- terminations actually made after exposures of 15, 60, 90, 120, 150, and 180 minutes. Milligrams Chlorine removed from i
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEA-SALTS ABOUT ARBACIA EGGS. 181 of eggs removes one third as much as in three. On the basis of these assumptions and the actual titrations, we can con- struct a curve showing the comparative amounts of chlorine which, under the conditions imagined, I of eggs would ab- stract from i of sea-water in one hour, if the rate of removal for that hour were constantly the rate deducible from the de- terminations actually made after exposures of 15, 60, 90, 120, 150, and 180 minutes. Milligrams Chlorine removed from i water in one hour at rate found at. (1, (3) Minutes FIG. i. Curve showing gradual loss in the power of eggs to abstract salts from sea-water. The number of titrations upon which the points indicated in the curve rest, is given in brackets. Clearly there is a steady ap- proach to zero. Since the rate of chlorine removal by eggs im- mersed for 180 minutes falls from the height which it had reached after 15 minutes it follows that the process of salt-abstraction is reversible. However, there is no equilibrium. We must suppose therefore that the chlorine-removing mechanism slowly breaks down. Within the time-limit of these experiments, the only part of the egg-system known to undergo dissolution is the jelly which surrounds each newly shed egg. This chorion disintegrates slowly in sea-water. Fortunately it can also be readily removed by moderate shaking. I therefore compared the chlorine deficits produced by equal volumes of normal and dechorionized eggs in equal volumes of sea-water. The experiment, of course, involves two errors: in the first place one cannot be certain that the jelly has actually been re- moved from every egg; and secondly, its removal from a con- siderable number renders it certain that a given volume of dechorionized ova will contain a larger number of cells than an. Please note that these images are extracted from scanned page images that may have be
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
