22 VERNON L. KELLOGG. 



treated with strong ammonium hydrate for periods of one half 

 minute or one minute. In two lots there was a beginning devel- 

 opment of one third of the eggs ; in the other four lots no increase 

 over the normal average. In one of the two lots showing stimu- 

 lation some of the eggs were left untreated and the increase in 

 proportion (reaching thirty-three per centum) of the developing 

 eggs occurred only in the treated portion of the lot.. In the un- 

 treated portion only four per centum of the eggs began develop- 

 ment. A fertilized lot treated with the reagent developed and 

 hatched normally. 



Stanford University, Calif. 



