(2) the visual records are ruled at a lower rate in some cases, but A., G., and Mo. show little difference;
(3) there is a tendency to speed up as the series progresses;
(4) the shorter lines are ruled with greater speed as a rule, though G. and Le. fail to show this phenomenon;
(5) The left-foot records show a higher speed-rate for all cases.
Among many interesting points that cannot be examined in this connection, such as relation of voluntary choice of rate to the main line of metronome records as regards accuracy, the fact of the higher rate of ruling for the left hand and foot stands most prominent.
Whether a record of head-movements to right or left, or other devices to compare the sides of the body or to contrast arm and leg speeds, will bear out this testimony is as yet unknown, so that the writer prefers to announce the result and not now fit theory to data. It may be said that the records were taken in reverse order and rearranged, as regards right and left foot or hand, and, in addition, the initial foot-movement varied with the subject, some being right and some left.
We ask finally: Is the time in which the greatest exactitude is produced, the same for every group of muscles; that is, has every motor apparatus the same natural rhythm? and: Is this natural rhythm a constant rapidity for all motor nerve-centres or does it depend upon the complexity and character of the movement?
The comparison will fall first on the averages and finally on the individual records.
The hand-movements show the following results:
Constant errors for 14 cm.: