WATER 



According to Lillie, among any lot of unfertilized eggs of 

 Arhacia which have been placed in 40 per cent, sea-water 

 are some which disintegrate after a very short time whilst 

 50 per cent, disintegrate after thirty minutes. From this 

 observation it is clear that, since more than half of the eggs 

 are killed by this dilution, the action of the 40 per cent, 

 sea-water on them is not reversible. Also, it is questionable 

 that this dilution is innocuous to those eggs that do not 

 disintegrate during these thirty minutes; they would 

 scarcely return fully to normal condition when brought 

 back to normal sea-water. Lillie points out that the eggs 

 after eighteen minutes exposure continue to swell, i.e., fail 

 to reach equilibrium with the diluted sea-water; instead 

 they break down. Thus this dilution gives information 

 concerning the rate of swelling only in injured eggs about to 

 die. The very obvious question arises, namely, how much 

 of the swelling is due to injury. It is thus difficult, if not 

 impossible, to draw conclusions from these experiments 

 concerning the behavior of normal eggs. Lucke and 

 McCutcheon in their many calculations of the swelling of 

 the Arhacia egg^ have likewise used 40 per cent, sea-water 

 as well as other solutions including non-electrolytes (sugars). 

 But inasmuch as to their work the same objections hold as 

 to that of Lillie — it is almost certain that the sugar solu- 

 tions used injured the cells further — we can not here con- 

 sider it, although, for their purpose, the demonstration of 

 the osmometer-properties of the egg, its moribund condi- 

 tion is of no consequence. 



In all my work I was at great pains to fix very definitely 

 the lowest limit of hypotonicity that a given marine egg 

 can withstand with recovery to the perfectly normal condi- 

 tion. The study of dead protoplasm as it exudes from an 

 egg membrane because of pressure put upon it either by 



1 Lucke and McCutcheon, iQ2g and earlier. 



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