Numerous writers have attested to the fact that the Babinski toe sign may be present in normal children up to 3 years of age. Most of the observations have been made on series of children of different ages rather than on repeated tests on the same children as they passed through successive ages. To the thusobserved incidence of Babinski reactions in normal infants have become appended a number of surmises:
It is generally inferred that in any individual infant the Babinski sign may be present at birth and may then remain demonstrable for an unpredictable time until it permanently disappears, before the age of 2 or 3 years.
It is usually agreed that this early present sign is due to lack, or irregularity, of myelinization of nerve fibers and that the disappearance of the sign marks the maturation of myelinization.
It has been repeatedly stated that the