142 FRANK R. LILLIE. 



tion) is TV/i 00,000 silver (nitrate), TV/33,333 gold (chloride), 

 TV/30,ooo mercury (chloride), TV/8,333 copper (chloride), v. 

 Euler and Svanberg (1920) studied the effects of heavy metals on 

 the inversion of cane sugar by saccharase, and determined among 

 many other things that mercury has about one thousand times 

 the poisonous effect of copper; the metallic ions in question enter 

 into combination with some constituent of the enzyme solution. 



The order of poisonous effects of mercury and copper on the 

 events of fertilization following membrane formation is thus the 

 same as that of the poisonous action of these metals on enzymes. 

 The concentrations also are of comparable magnitude (cf. 

 McGuigan's data above), v. Euler and Svanberg found the 

 range for HgCl 2 between complete inhibition of the ferment 

 and no effect to lie between I part in 116,600 and I part in 

 1,166,000 of the solution (compare Table VII. of this paper). 

 There is thus a rather surprisingly close agreement in the effective 

 concentrations; so that it is reasonable to conclude that the 

 effect of mercury and copper on fertilization following membrane 

 formation may be due to enzyme poisoning. 



The inhibiting effect of mercury and copper on the initial 

 stages of the fertilization reaction is in the inverse order, and 

 does not, therefore, correspond so well to the enzyme analogy. 

 The results emphasize the strong contrast between the initial 

 and the subsequent events of the fertilization process, which is 

 found also in the phenomena of specificity (Lillie, 1919, 1921), 

 and in other phenomena of fertilization. 



LITERATURE. 



v. Euler, H., und Svanberg, Olaf 



'20 Ueber Giftwirkungen bei Enzymreaktionen. I., Inaktivierung der Saccha- 

 rase durch Schwermetalle. Fermentforschung, III. Jahrgang, pp. 330- 

 393. II., Inaktivierung der Saccharase durch organische Stoffe, ib., IV. 

 Jahrg., pp. 29-63. III., Ueber den Einfluss von Kupffersulfat auf die 

 Autolyse der Hefe, ib., pp. 90-96. IV., Elektrometrische Messungen 

 ueber die Bindung des Silbers und des Kupffers an Saccharase und an 

 andere organische Verbindungen, ib. , pp. 142-183. 



McGuigan, Hugh 



'04 The Relation between the Decomposition Tension of Salts and tbesl 

 Antifermentation Properties. The American Journal of Physiology, 

 Vol. X., pp. 444-451. 



