Av.=2.02 P. E. M.=4.40 P. E. Is there, after operation, an improvement in motor control and attention, and a lessening of fatiguability as these may be demonstrated in the tapping test? Table VI gives the number of taps in the first half minute of tapping for both groups before and after the six months interval. The test group suffers an average loss of 2.24 taps, and a median loss of 2. The average loss of the control group is 2.33, and the median 2. TABLE VI Gain in Grip--6 Months--16 Pairs N[16] Test Group (A) Control Group (B) Test 1 Test 2 Gain Test 1 Test 2 Gain A-B 10 12.5 11 -1.5 10 15 5 -6.5 27 9 6 -3 8 9 1 -4 1 13 12 -1 11 13 2 -3 14 16 15 -1 22 24 2 -3 2 9 9 0 10 12 2 -2 9 10.5 13 2.5 16.5 21 4.5 -2 7 7 6.5 - .5 9 10 1 -1.5 16 19 17.5 -1.5 10 10 0 -1.5 3 12.8 14.5 1.7 14 15 1 .7 13 26.5 28.5 2 22 23 1 1 24 19 20 1 15 15 0 1 19 22 21 -1 15 12 -3 2 22 18 22.5 4.5 19.5 21.5 2 2.5 11 11 15 4 11.5 11.5 0 4 21 16.5 16.5 0 19 15 -4 4 23 11.5 15.5 4 14.5 14 - .5 4.5 Av. 14.58 15.22 .62 14.19 15.06 .875 - .24 M 0 1 -1.0 75%ile 3 2 2.25 25%ile -1 0 -2.5 Q 2 1 2.38 P. E. (distribution) 1.58 1.02 2.49 P. E. (average) +-.40 +-.26 +-.48 Av.= -.50 P. E. M.= -2.08 P. E. There is practically no change then in the tapping ability of either group. The high unreliability of the difference (P. E. = +- 3.10) is noteworthy. It would seem that incidental causes have a much greater effect upon tapping ability than can be demonstrated as resulting from the removal of adenoids and tonsils.