THEORY OF STATISTICS. 
the distribution, in such a way as to suggest that the ideal 
curve is tangential to the base. Cases of greater asymmetry, 
suggesting an ideal curve that meets the base (at one end) at a 
finite angle, even a right angle, asin fig. 9 (8), are less frequent, 
but occur occasionally. The distribution of deaths from diphtheria, 
according to age, affords one such example of a more asymmetrical 
kind. The actual figures for this case are given in Table XIL., and 
illustrated by fig. 14 ; and it will be seen that the frequency of 
deaths reaches a maximum for children aged “3 and under 4,” 
the number rising very rapidly to the maximum, and thence 
falling so slowly that there is still an appreciable frequency for 
persons over 60 or 70 years of age. 
TABLE XII. —Showing the Numbers of Deaths from Diphtheria at Different 
Ages in England and Wales during the Ten Years 1891-1900. (Supple- 
ment to 65th Annual Report of the Registrar-General, 1891-1900, p. 3.) 
See Fig. 14. 
Number of 
. Deaths between Number 
Attelin Wears, Given Limits per Annum. 
of Age. 
Under 1 year 4,186 4,186 
- 10,491 10,491 
2- 11,218 11,218 
3- 12,390 12,390 
1- 11,194 11,194 
i 23,348 4,670 
10- 4,092 818 
15— 1,123 295 
20~ 585 
25- 786 
35- 512 
45- 324 
55— 260 
65— 127 
75 and upwards 35 
Total 80,671 
15. The extremely asymmetrical, or J-shaped,” distribution, the 
class-frequencies running up to a maximum at one end of the 
range, as in fig. 15. 
This may be regarded as the extreme form of the last distribution, 
from which it cannot always be distinguished by elementary 
methods if the original data are not available. If, for instance, 
the frequencies of Table XII. had been given by five-year intervals 
08