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WILSON GEE. 



minute or less. This factor held constant in the alcohol solutions 

 in distilled water to as high as twenty per cent. In the earlier 

 part of the experiments of the season of 1915, the spermatozoa 

 were treated with the following strengths of alcohol in distilled 

 water: o.i per cent., 0.2 per cent., 0.5 per cent., I per cent., 

 1.5 per cent., 2 per cent., 2.5 per cent., 2.8 per cent., 3 per cent., 

 3.5 per cent, and 4 per cent. At the end of a minute, in most 

 instances, the spermatozoa were inert and consequently incapable 

 of fertilizing an egg. It was found possible to activate them, 



17 



FIG. 1 6. An embryo from same lot as the one in preceding figure with only 

 remains of embryo disintegrating over yolk mass. 



FIG. 17. A microphthalmic monster of six days treated with fifteen per cent, 

 alcohol in sea water for fifteen minutes at twenty minutes after fertilization. 



however, by the use of a weak sodium hydroxide solution (0.6 c.c. 

 N/io NaOH -f- 50 c.c. sea water, or better, a somewhat stronger 

 solution 6 drops N/io NaOH + 10 c.c. sea water). Just a drop 

 of such a solution set the spermatozoa active in a short time, and 

 in the treatments with the lower concentrations of alcohol, they 

 were enabled to fertilize the eggs with a considerable percentage 

 developing. 



A large proportion of the spermatozoa could be activated in 

 the treatments of lower concentrations and continue active for 

 several minutes. It became evident therefore that best results 

 were likely to be obtained by treatments of fifteen and twenty 

 per cent, solutions. It was found possible to treat the spermatozoa 



