2. When all conditions were the same except the presence or absence of the adsorbent and the velocity of hydrolysis was relatively large, then the amount hydrolyzed in a given time was less in the presence of the ad- sorbent. 3. The decrease in rate appears to be due largely to the uneven dis- tribution of the invertase in the reaction mixture, because by preventing the settling of the adsorbent combined with the enzyme the extent of the retardation was diminished. ...