| Males | Females | Both sexes | ||||
| 1851-60 | 460 | 545 | 503 | |||
| 1861-70 | 487 | 566 | 527 | |||
| 1871-80 | 474 | 547 | 512 | |||
| 1881-90 | — | — | 451 |
No other epidemic malady has shown the same excess of female deaths in proportion to the numbers of the sex living, diphtheria being the only other that shows an excess at all.
The excess of deaths by whooping-cough among female infants was roughly shown by Watt in 1813, viz. 975 females to 842 males in the registers of the Glasgow High Church, College Church and the North-Western Cemetery, the relative numbers of the sexes living at the respective ages being then unknown. In all Scotland in 1889 the ratio was 1043 male deaths to 1225 female. The singular difference between the sexes in this respect is almost certainly related to the corresponding differences in the formation and development of the larynx, the organ which gives character, at least, to the convulsive cough of children. The expansion of the larynx in boys, which becomes so obvious at puberty and remains so distinctive of the male sex, is one of those secondary sexual characters which begin to differentiate quite early in life, and are probably congenital to some extent. It is not known whether female children are more often attacked than males; but it is probable that they are predisposed both to acquire coughs of the convulsive suffocative kind and to have their lives shattered by the attack—for the same anatomical and physiological reasons, namely, the imperfect development of the posterior space of the glottis with the spasmodic closure by reflex action[1242]. The deaths have been nearly all under the age of five.
Deaths by Whooping-cough per million living at the respective age-periods.
| 0-5 | 5-10 | |||
| 1851-60 | 3624 | 174 | ||
| 1861-70 | 3766 | 152 | ||
| 1871-80 | 3652 | 135 |
These proportions are almost the same as those given by Watt in 1813 from three of the Glasgow registers.
| Period | Deaths by whooping-cough | Under five | Five to ten | Above ten | ||||
| 1783-1812 | 1817 | 1713 | 98 | 3 |
Most of the deaths are in the first year, and in a rapidly declining ratio until the fifth, according to the following rates per million of male children living at each age-period (these figures are for a single year, 1882):
| Under one | One to two | Two to three | Three to four | Four to five | ||||
| 3039 | 2115 | 826 | 433 | 248 |
The mortality from whooping-cough falls very unequally on town and country. Thus, in Scotland in 1889, it caused 2268 deaths, being 3·13 per cent. of the deaths from all causes, and equivalent to a rate of ·58 per 1000 living. The death-rate varied as follows: ·91 in the eight principal towns, ·46 in the group of large towns, ·45 in the group of small towns, ·25 in the mainland rural districts, and ·08 in the insular rural districts. In England, the capital has more than its share of deaths from whooping-cough, Lancashire coming next, while the death-rates of Monmouthshire, Cornwall and Warwickshire are also a good deal above the mean of the whole country. The lowest death-rates are found in the purely agricultural counties.