EGG SECRETIONS OF ARBACIA AND ASTERIAS 



473 



the fact that ''the efficiency of the agglutinin contained in 

 fertihzin, Hke pepsin (Euler, p. 132), varies with the square root 

 of the concentration." The efficiency may be measured by the 

 length of time the sperm remain agglutinated and the concen- 

 tration by Lillie's units of strength (Lillie, '14). Curves may 

 be plotted by letting x equal the concentration and y the efficiency. 

 The average of twelve such curves gives a figure which corre- 

 sponds very closely to the curve of the equation ?/- = ILx, or, 

 y = c-\/x (fig. 1). The curves are nearly identical in the ower 

 concentrations, where experimental determination is more accu- 



2^8 /6 



Fig. 1 The solid line is the curve of the equation y = c V ^- The broken line 

 represents the results of twelve experiments. 



rate and where the greater number of values is averaged. They 

 coincide in all parts within the limits of experimental error. It 

 is safe to conclude, therefore, that the sperm agglutinin resembles 

 enzymes in the relation between efficiency and concentration. 



d. Tests for enzymes. If, as the radiation tests suggest, 

 enzjones are present, it seemed likely that we might be dealing 

 with oxidase or catalase or both. The f oiTner gives a blue reaction 

 with guaiac, especially if hydrogen peroxide is added. If Arbacia 

 secretion made from fresh eggs is tested with guaiac plus H2O2, 

 no blue color appears. If the secretion s made from eggs which 

 have stood for some time, so that some of them are cytolysed, 



