The researches made by various authors in regard to the growth of the brain are not rigorously in accord as to the limits of volume: but they do agree as to the rhythm of growth.
Welcker gives the following figures:
WEIGHT OF THE BRAIN IN GRAMS
(According to Welcker)
| Age | Males | Females |
|---|---|---|
| At birth | 400 | 360 |
| Two months | 540 | 510 |
| One year | 900 | 850 |
| Three years | 1,080 | 1,010 |
| Ten years | 1,360 | 1,250 |
Accordingly, the weight of the brain is doubled before the end of the first year; according to Massini it is very nearly doubled at the end of the first six months:
MASSINI'S FIGURES AS TO THE WEIGHT OF THE BRAIN
| Age | Total weight | Increase | |
|---|---|---|---|
| At birth | 352 | 68 | 279 |
| First month | 420 | 211 | |
| From first to third month | 631 | ||
| From third to sixth month | 675 | 44 | 63 |
| From sixth month to 1 year | 694 | 19 | |
Fig. 78.—Spheroidal cranium lateral norm (Sergi's collection).
