Kinetics of the reaction between trypsin and the pancreatic trypsin inhibitor

407 the shoot apex (95 %) and the lowest in the cotyle- dons (43 %).The cotyledons are no longer the main source of inositol in the plant.In the ungerrninated seed 5-2 % of the inositol is in the free state, whereas in the young plant this has risen to 74 %.There has been an over-all increase of 910%0 in the free inositol, after taking account of the losses in dry weight on germination, but a loss of 16-2 % in the total ino- sitol.This result is in contrast with that of Cheldelin & Lane (1943), who found that with lima beans germinated for 48 hr. an increase in inositol occurred.Since their method of determining inositol was that of digestion with papain and Taka diastase, their result is open to criticism.As the leafdevelops, the concentration of free and total inositol increases, with a corresponding in- crease in the absolute amounts (Table 4).The fully open green leaves collected at different times of the day do not show any changes which might be ascribed to a diurnal variation.SUMMARY 1.A study has been made of the distribution of free and combined inositol in both the unger- minated bean seed and the young bean plant.2. In the ungerminated seed only 52 % of the total inositol is in the free state, and this rises to 74 % in the young plant.3. A concentration gradient of inositol down the plant from the shoot apex to the roots has been demonstrated.4. The concentration of inositol in the leaves increases with progressive stages of growth.