| No. of Population. | Years required to produce it. | |
|---|---|---|
| A | B | |
| 4 | 27 | 30 |
| 5 | 54 | 60 |
| 6 | 81 | 90 |
| 32 | 108 | 120 |
| 64 | 135 | 150 |
| 128 | 162 | 180 |
| 256 | 189 | 210 |
| 512 | 216 | 240 |
| 1,024 | 243 | 270 |
| 2,048 | 270 | 300 |
As regards the men, it is also probable that those who marry at thirty will on the whole be fathers of smaller families than those who marry at twenty-five, even did they mate with women of the same age. Of this, however, I cannot adduce reliable statistical evidence.
[Their Infant Mortality is Greater.]
The lower classes appear, therefore, to be more fertile; they more frequently marry, and they marry at earlier and more fertile ages.
On the other hand it must at once be admitted that they manage to rear a smaller percentage of their off-spring. The mortality amongst the infants and children is often alarmingly great through ignorance and neglect on the parent’s part.
While, therefore, the lower classes are undoubtedly the most fertile, it is not certain how far this is counterbalanced by the lower mortality which exists among the children and youth of the upper classes.
[Artificial Restriction of the Family.]
That the counterbalance is not complete is generally believed, and we must view with dismay any agencies which tend still more to make the middle and upper classes sterile relatively to the lower. There can be little doubt that this has recently, and to an increasing extent, been brought about by the wilful avoidance, on the part of the parents of the middle and upper classes, of the full duties of parenthood. It can no doubt be urged that whereas, in many instances, the care of one or two children can be undertaken in such a manner as to insure their careful upbringing and education, the rearing of a large family would be quite beyond the power of the parents, and would lead to their neglect, or deprivation of some of those advantages which we have already seen to be so necessary for life’s struggle.
However true this may be, and however we may sympathise with a parent’s desire to do his best by his offspring, it is likewise true that this is an important means, and probably one of greatly increasing importance, by which the upper and middle classes are becoming, relatively speaking, sterile. It is probable, too, that this sterility will be mostly found in the case of those who rise in life and have a longer and more difficult battle to fight, and who have, therefore, most cause to avoid unnecessary complication.