AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIBLIOGRAPHIC SERVICE, FEBRUARY 28, IQ2I. 



EFFECT OF VARIATIONS IN OXYGEN TENSION ON 

 THE TOXICITY OF SODIUM CHLORIDE ISOTONIC 



TO SEA WATER. 



ISAAC STARR, JR., 

 MARIXE BIOLOGICAL LABORATORY. 



Loeb first observed that he could protect fertilized Arbacia eggs 

 for some time from the toxic action of a NaCl solution, isotonic 

 to sea water, by removing the oxygen from the solution or by 

 adding a little KCN. 1 Cyanide also protects unfertilized Arbacia 

 eggs against injury by isotonic solutions of various sodium salts, 

 and anaesthetics in appropriate concentrations have' a similar 

 effect. 2 Experiments with Arenicola larvae have given similar 

 process being in some manner connected with the destructive 

 results. 3 These results indicate the probability of an oxidative 

 process being in some manner connected with the destructive 

 reaction. 



The following experiments were undertaken to determine the 

 effect of varying the oxygen tension on the toxicity of NaCl 

 isotonic to sea water. The form chosen to work with was the 

 larva of the marine worm, Arenicola cristata, a free swimming 

 trochophore of three body segments, about I /T, mm. in length. 

 \\ hen normal it is almost constantly in motion, showing ciliary 

 action and bendings to one side, or strong muscular contractions. 

 The larva? employed were all in the swarming stage and were 

 collected from the lighted side of the culture dish, just below the 

 surface of the water, where they gather in large numbers. As 

 they remain in this stage only from three to four days before 

 developing another segment and sinking to the bottom, a fairly 

 homogeneous culture is obtained. When these animals are placed 

 in pure sodium chloride isotonic to sea water they promptly con- 



1 Loeb, J., Science, 1910, XXXII., 411; Biochemical Zeitschrift, 1910, 

 XXIX., p. So. 



- Lillie R. S., Amer. Joitrn. Physio!., 1912, XXX., p. i. 



3 Lillie, R. S., Amer. Joitrn. Physio!.. 1912, XXIX., p. 372, and 1913, XXXI., 

 P- 255. 



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