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HELEN DEAN KING. 



tions under which fertilization was effected, however, prevented 

 the eggs from absorbing any considerable amount of water during 

 this period. The early development of these eggs was not inter- 

 fered with by the abnormal conditions under which they had 

 been fertilized, as in both series segmentation was normal and but 

 slightly later than that of the control lot. The mortality among 

 the older embryos was considerable; and somewhat greater in 

 lot Y where the eggs had remained the longer time out of water. 

 The results obtained in this series of experiments are brought 

 together in Table III. 



TABLE III. 

 EGGS FERTILIZED DRY. 



In each case, as the above table shows, a percentage of females 

 was obtained that is considerably higher than that in the con- 

 trol; the higher percentage of females being found among the 

 individuals of lot Y which had developed from the eggs that had 

 remained the longer time out of water. The possible bearing of 

 these results will be considered in connection with the results of 

 the experiments in series B. 



Series B. The second method used to ascertain whether les- 

 sening the water content of the egg at the time of fertilization 

 would produce any alteration in the sex ratio was suggested to 

 me by Dr. E. G. Conklin, and consisted in subjecting the unfer- 

 tilized eggs to the action of salt or of sugar solutions. These 

 solutions, being hypertonic, would tend to extract water from 

 the eggs or to check the absorption of w r ater by the eggs. To 

 attempt the fertilization of eggs in these solutions would be futile, 

 since Loeb ('92) has shown that the addition of even 2 per cent. 

 NaCl to sea-water anaesthetizes the spermatozoa of Arbacia, 

 and a much weaker solution would probably have a similar effect 

 on the spermatozoa of amphibians. 



Several preliminary series of experiments made during the 

 spring of 1909 were complete failures, since either the eggs were 



