On the Isolation of Oocytase. 



9i 



yellowish fluid thus obtained yielded no precipitate or opalescence 

 upon the further addition of Na2SO< and was therefore free from 

 barium. To this fluid were added 4 volumes of acetone. A light 

 flocculent precipitate was formed at once which settled readily. 

 This was collected upon a hardened filter, washed in alcohol and 

 ether, and dried for 3 Yi days over H2SO4 at 36 0 C. 



The substance thus obtained does not dissolve in sea-water. 

 It dissolves readily in iV/10 HC1 and remains in solution upon 

 neutralization. To this solution sufficient 2Y1M NaCl was 

 added to render it isotonic with sea-water and the solution (0.5 

 per cent.) thus obtained was diluted to 1, H» • • • > etc -» by the 

 addition of sea water. On adding sea water, the mixture becomes 

 very opalescent but the substance is not precipitated. 



Eggs of Strongylocentrotus purpuratus which have not under- 

 gone previous sensitization are fertilized and agglutinated by 

 solutions of this substance in dilutions of from I part in 200 to I 

 part in 800. Eggs which have been sensitized by immersion for 

 4 minutes in M/2 CaC^ are fertilized and agglutinated by dilutions 

 of from 1 part in 200 to I part in 1,600. Eggs which have been 

 sensitized by immersion for 4 minutes in M/2 SrCU are agglutinated 

 by dilutions of from I part in 200 to I part in 25,000. The 

 sensitizing action of SrC^ and CaCU is clearly seen to reside in 

 their power to precipitate the fertilizing agent upon the egg. 



Since this substance is thermostable, withstanding 18 hours' 

 exposure to a temperature of 50 0 without destruction, and there 

 is some reason for suspecting that it is not present as such in 

 circulating blood but is discharged from white corpuscles in shed 

 blood, it would appear to present many analogies to the cytases or 

 cell-liquefying substances found by Metchnikoff in white cor- 

 puscles. Accordingly, I propose that it be called "Oocytase." 



