400 



WILSON GEE. 



in these cases is much lowered, those that do develop seem to be 

 more vigorous. This is indicated by the large percentage de- 

 veloping to the sixth day as normal individuals. 



In the summarized results of these four experiments (see 

 Table VIII.), it appears that the treatments of one minute 



TABLE VIII. 



SUMMARY OF RESULTS OF FIFTEEN PER CENT. ALCOHOL IN SEA WATER ON THE 



SPERM OF Fundidus. 



duration have a greater effect than does the longer treatment. 

 The shorter treatment seems to cripple the weaker spermatozoa, 

 which fertilize the eggs and result in sub-normal individuals; 

 while the longer treatment weeds out the weaker ones, the 

 strongest ones being unaffected and leading to normal develop- 

 ment when they fertilize the egg. 



(c) Comparative Effects of Treatments of Different Lengths. One 

 method used in determining whether the treatment was effec- 

 tive on the spermatozoa was to give them equal doses for different 

 lengths of time. In such an experiment the effect on the eggs 

 should be a constant factor, and a differential thereby established 

 between the injury of the spermatozoa treated for one minute and 

 those treated for five minutes or longer. Five such series were 

 carried out and the combined results are given in tabulated form 

 (see Table IX.). 



Examination of these data will indicate that while the per- 

 centage sub-normal is not very large in any instance, the greater 

 effect is with the one minute treatment. The longer treatments 



