146 T. H. Morgan. 



There was another series in this set in which the ether was 

 stronger (about one-half saturated). None of the eggs from this 

 solution segmented, but they became filled with clear spots. In 

 another check series, self-fertilized but kept in sea-water, none 

 of the eggs developed. 



Experiment X. Sperm alone was put into ether solutions of 

 6, 4, I, 0.5 per cent. It was removed (along with some of the 

 surrounding fluid) and added to the eggs after 2 and 10 minutes. 



Ether 2 min. lomin. 



6. o o 



4. o o 



I. 20 10 



0.5 4 50 



It appears from this experiment that it suffices to put only the 

 sperm into the ether-solutions to bring about self-fertilization, but 

 it should not be overlooked that a certain amount of the ether is 

 carried over with the sperm when the latter is added to the eggs. 

 The amount, it is true, will be small, since the eggs stand in 

 water which further dilutes the ether, but so long as this source 

 of error is present, and it is very difficult to remove it entirely, 

 the result does not show conclusively that the ether acts on the 

 sperm alone, although I think this is the more probable inter- 

 pretation. 



A check series of experiments was also made in which both 

 eggs and sperm were put into solutions of the same strength as 

 those given above, for 15 minutes and then removed to water. 



Ether. 15 min. 



6. o 



4. o 



I. 100 (but only ten eggs present.) 



0.5 90 



It is evident from both of the foregoing tables that only the 

 weak solutions were effective, and from the first table it appears 

 that this must have been the result of injury to the sperm. It 

 can easily be seen that the eggs also are killed in a few minutes 

 by a 6 per cent, solution of ether. 



