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ALVALYN E. WOODWARD 



though already published (Richards and Woodward), may be 

 summarized here. Equal amounts of the secretion were placed 

 in four open dishes. One was kept shielded from x-rays for a 

 control, one was radiated two minutes, another five minutes, 

 and the third, fifteen minutes. The agglutinating power of each 

 was then tested with fresh sperm suspension, by finding the dilu- 

 tion necessary to bring about a unit reaction. It was found that 

 the secretion which had been radiated two minutes had the great- 

 est agglutinating power. That which had been radiated five 

 minutes was about the same as the control, while radiation for 

 fifteen minutes decreased the efficiency of the agglutinin. These 



TABLE 4 



The effect of x-radiation on the parthenogenetic power of fertilizin 



results correspond closely with those previously obtained by 

 Richards ('14) when enzymes were radiated, and suggest very 

 strongly that sperm agglutinin may also be an enzyme. 



The effect of radiation of the agglutinin wears off in two or three 

 hours, the length of time during which eggs should be exposed to 

 the secretion in order to produce autoparthenogenesis. If the 

 effect on the egg activator is equally transitory, one would not 

 expect that radiation would greatly affect its parthenogenetic 

 power. Experiments 3 and 5, table 4, suggest, however, that 

 the effect of radiation on the parthenogenetic power of fertilizin 

 is similar to that on its agglutinating power. 



c. The relation between concentration and agglutinating power. 

 The work of 1914 (Richards and Woodward) also brought out 



