808 SCIENCE. 
typical experiment is that of tapping on a 
key in time to a sounder-click, the move- 
ment of the click and that of the movement 
of the finger being registered on a drum. 
Regulated rhythmic action differs from 
free rhythmic action mainly in a judgment 
on the part of the subject concerning the co- 
incidence of his movements with the sound 
heard (or light seen, etc.). This state- 
ment, if true, at once brushes aside all 
physiological theories of regulated rhythmic 
action. One of these theories is based on 
the assumption (Ewald) that the laby- 
rinth of the ear contains the tonus-organ 
for the muscles of the body. It asserts that 
vibrations arriving in the internal ear affect 
the whole contents including the organ for 
the perception of sound and the tonus- 
organ. Thus, sudden sounds like drum- 
beats or emphasized notes would stimulate 
the tonus-organ in unison, whereby corre- 
sponding impulses would be sent to the 
muscles. This theory has very much in 
its favor. It is undoubtedly true that such 
impulses are sent to the muscles. Thus at 
every loud stroke of a pencil on the desk I 
can feel a resulting contraction in the ear 
which I am inclined to attribute to the WM. 
tensor tympani. Likewise a series of drum- 
beats or the emphasized tones in martial or 
dance music seem to produce twitchings in 
thelegs. Féré has observed that, in the case 
of a hysterical person exerting the maximum 
pressure on a dynamometer, the strokes of 
a gong are regularly followed by sudden 
increased exertions. Nevertheless, these 
twitchings are not the origin of the move- 
ments in regulated rhythmic action. For 
many years I have observed that most per- 
sons regularly beat time just before the 
signal occurs; that is, the act is executed 
before the sound is produced. Records of 
such persons have been published (e. g., 
New Psychology, p. 182), but their appli- 
cation to the invalidation of the tonus- 
theory was first suggested by Mr. Ishiro 
[N. 8. Von. X. No. 257. 
Miyake. This does not exclude the use of 
muscle sensations, derived from tonus- 
twitches, in correcting movements in regu- 
lated rhythmic action, although they pre- 
sumably play a small or negligible part as 
compared with sounds. 
Another argument in favor of the sub- 
jective nature of regulated rhythmic action 
is found in the beginning of each experi- 
ment on a rhythm of a new period; the 
subject is quite at loss for a few beats and 
can tap only spasmodically until he obtains. 
a subjective judgment of the period. If the 
tonus-theory were correct, he should tap 
just as regularly at the start as afterward. 
The conclusion seems justified that regu- 
lated rhythmic action is a modified free 
rhythmic action, whereby the subject re- 
peats an act at what he considers regular 
intervals, and constantly changes these in- 
tervals to coincide with objective sounds 
which he accepts as objectively regular. 
In free rhythmic action there is one inter- 
val which on a given occasion is easiest of 
execution by the subject. This interval is 
continually changing with practice, fatigue, 
time of day, general health, external con- 
ditions of resistance, and so on. 
“Tt has long been known that in such 
rhythmic movements as walking, running, 
etc., a certain frequency in the repetition of 
the movement is most favorable to the ac- 
complishment of the most work. Thus, to 
go to the greatest distance in steady travel- 
ing day by day the horse or the bicyclist. 
must move his limbs with a certain fre- 
quency ; not too fast, otherwise fatigue cuts. 
short the journey, and not too slow, other- 
wise the journey is made unnecessarily 
short. This frequency is a particular one 
for each individual and for each condition 
in which he is found. Any deviation from 
this particular frequency diminishes the 
final result.’’ 
It is also a well-known fact that one rate 
of work in nearly every line is peculiar to 
