Note 122 — Chapter III · THE RATE OF GROWTH
Reading edition
Amer. J. of Anatomy, VIII, pp. 319–353, 1908. Donaldson (Journ. Comp. Neur. and Psychol. XVIII, pp. 345–392, 1908) also gives a logarithmic formula for brain-weight (y) as compared with body-weight (x), which in the case of the white rat is y = ·554 − ·569 log(x − 8·7), and the agreement is very close. But the formula is admittedly empirical and as Raymond Pearl says (Amer. Nat. 1909, p. 303), “no ulterior biological significance is to be attached to it.”