ACTION OF THE HYPERTONIC SOLUTION 109 



The larvae were crippled by too long an exposure. I also 

 found that one could even obtain larvae if a trace of HC1 was 

 added to the hypertonic solution. I have not yet determined 

 the lower limit of the concentration of hydroxylions in the 

 hypertonic solution. 1 



6. We will now proceed to the discussion of an apparent 

 contradiction between the results of this and of the previous 

 chapter. In the latter we saw that the eggs can be made to 

 develop after membrane formation by keeping them for three 

 hours or more in water that is poor in oxygen, or by preventing 

 the oxidations by the addition of KCN. In this chapter we 

 saw that the eggs after membrane formation can be made to 

 develop by putting them afterward into hypertonic sea-water 

 for some thirty to fifty minutes; but that this is only possible 

 if the hypertonic sea-water contains a sufficient amount of free 

 oxygen. How are these apparently contradictory statements to 

 be reconciled? 



The essence of the activation of the unfertilized egg con- 

 sists in the production of membrane formation. This process 

 is certainly not one of oxidation, since it can take place in the 

 absence of oxygen or in the presence of KCN. Perhaps it 

 depends ultimately upon a purely physical process (such as the 

 liquefaction of a lipoid or the dissociation of a [hypothetical] 

 lipoid-protein combination). 



As soon as this process has taken place, development sets 

 in in the egg. Why this is the case, we do not at present know. 

 But at the same time this process leaves the egg in an abnormal 

 or sickly condition. If the egg begins to develop while in this 

 injured condition, it disintegrates. But if we prevent the 

 egg from developing for some hours, by depriving it of oxygen, 

 or stopping oxidations by the addition of KCN, the egg can 

 develop normally. We must seek the reason for this in the 



1 Loeb, "Zur Analyse der osmotischen Entwicklungserregung unbefruchteter 

 Seeigeleier," Pfliiger's Archiv, CXVIII, 197, 1907. 



