ACTIVE FROM INACTIVATED BACTERIOPHAGE 109 



curves for low multiplicities, up to x = 0.5; for higher multiplicities they fall 

 below the corresponding curves for y calculated for the same number of units. 

 We can actually find, for each value of x, a curve for y — for the same n but 

 corresponding to a lower x— which fits the experimental curve. The correspond- 

 ing theoretical curves are drawn in figures 5-7. This indicates that groups of 

 more than two particles collaborate in reactivation as if they consisted of a 

 lower but definite number of particles. 



It is interesting to notice that the systematic deviation from theory for 



W I 



10" 



10" 



10' 



10 



"4 



2 4 6 X 



Fgure 4.— Same as figure 2, for phages T6 and T6r. The theoretical curves for 

 y correspond to w=30. 



282 



