and so many years and no months were omitted, because there is a considerable probability that in many cases of this sort the number of months was not recorded. For this reason the number of children corresponding to the full years and no months is too small. It might have been better to group the material as follows: 11, 0, 1 months; 2, 3, 4 months; 5, 6, 7 months: 8, 9, 10 months; but I did not do so, in order to preserve the comparability with other series which extend over the whole year. The records of ages show that in order to obtain accurate results the question ought not to be simply for years and months, but we should ask for the age at the last birthday, age at the coming birthday, and the date of the birthday. When we simply ask for years and months, the person answering the question will often first give the age at the nearest birthday, particularly when the approaching birthday is not far distant, and then add the number of months passed since the last birthday, thus introducing an error of a whole year. This was noticed to occur in the Worcester measurements that were repeated after the lapse of a year, Accuracy can be attained only by the three questions given before. The following are the tables of statures: Statures of Toronto boys, grouped in quarter-year periods. Number of boys of the following ages. Height in centimeters. 5 years and 6 to 8 9 to 11 0 to 2 3 to 5 6 to 8 9 to 11 0 to 2 3 to 5 6 to 8 9 to 11 mos. mos. mos. mos. mos. 2 173 20201 103 104 105 106 107 108 109 110 111 112 113 114 69941 10 13 8 1 1 137 Cases 42 82 102 Average height. 103.9 104.5 107.3 108.1 109.7 110.3 111.1 113.1 114.9 115.5 117.7 118.3 Mean varia tion..... +4.44 ±4.70 +5.07 ±4.60 ±4.59 +4.48 ±4.29 +5.25 +4.17 ±4.67 ±4.83 £5.40 Statures of Toronto boys, grouped in quarter-year perioas-Continued. Number of boys of the following ages. Height in centimeters. 8 years and 9 years and 10 years and 0 to 2 3 to 5 6 to 8 9 to 11 0 to 23 to 5 6 to 8 9 to 11 0 to 2 3 to 5 6 to 8 9 to 11 mos. mos. mos. mos. mos. mos. mos. mos. mos. mos. mos. mos. tion.. 8848231 12 1 6 11 11 14 16 16 11 20 19 14 16 12 11 6218025781 21 1 1 1 10 18 11 14 13 8 11 1 +5.08 +6.01 +5.31 ±5.13±4.47 +5.43 ±5.51 +5.99 +6.00 +5.97 ±6.01 6.09 Statures of Toronto girls, grouped in quarter-year periods. Number of girls of the following ages. Height in centimeters. 85 94 95 97 0 to 2 3 to 5 6 to 8 9 to 11 0 to 2 3 to 5 6 to 8, 9 to 11 0 to 2 3 to 5 6 to 8 9 to 11 mos. mos. mos. mos. mos. mos. mos. mos. mos. 5 years and 2000 5 8 11 14 BOBOTTOgao 6 3 1 1 2 1 103.6 104.2 104.9 106.8 108.9 109.4 110.6 111.6 114.9 115.7 115.9 +4.82 +4.01 4.69 +4.97 ±4.13 +5.25 +4.61 +4.93 ±5.00 ±4.94 ±5.16 +5.74 |