Action of the Hypertonic Solution 103 



It is clear that the temperature coefficient Qm is higher than 

 2, in the neighborhood of 3, and that it quickly increases at 

 temperatures which are close to 0°, and reaches the value 5 or 

 perhaps still higher values.^ Hence the order of magnitude of 

 the temperature coefficient indicates that we are dealing here 

 with a chemical effect of the hypertonic solution. 



4. We are in a position to determine more closely the nature 

 of the chemical processes upon which the efficiency of the hyper- 

 tonic solution depends, namely oxidations. The efficacy of 

 the hypertonic solution is completely removed if we inhibit 

 oxidations in the egg by means of potassium cyanide or by the 

 withdrawal of oxygen.^ 



It can be shown that the treatment of eggs after artificial 

 membrane formation with hypertonic sea-water remains in- 

 effective if the latter contains an insufficient amount of oxygen, 

 or if it contains KCN. After removal from such solutions, 

 the eggs behave as if only membrane formation had been 

 produced, i.e., they begin to develop, but quickly disintegrate 

 in the manner described in the previous chapter. A single 

 example will suffice to illustrate this. 



Unfertilized eggs of S. purpuratus were placed for one and 

 one-half to two minutes in 50 c.c. of sea-water-f-3 c.c. N/10 

 butyric acid, and, as usual, all formed a perfect fertilization 

 membrane upon transference to sea-water. They were then 

 distributed over the following solutions: 



(1) 50 c.c. of sea-water-|-8 c.c. of 2^ m NaCl 



(2) 50 c.c. of sea-water+8 c.c. of 2| m NaCl+2 c.c. 1/20 of 1 per 

 cent KCN. 



After 30, 40, 50, 135, 195, 285, 335, 385, 450, and 1,320 minutes, 

 a sample of the eggs was transferred to normal sea-water. The 

 temperature was 18° C. For the eggs in the first solution, the 



1 Loeb, Untersucjiungen, p. 494; University of California Publications, Physiol- 

 ogy, III, 39, 1906. 



»Loeb, Piochem. Zeitschr., I, 194, 1906. 



