present a certain amount of heart block, not all the stimuli
reaching the ventricle. There may be a ratio of auricular
contractions to ventricular contractions, according to Fulton, of
2:1, 3:1, 4:1 and 5:1, the 2:1 ratio being most common.

Of course it is generally understood that children have a higher
pulse rate than adults; that women normally have a higher pulse rate
than men at the same age; that strenuous muscular exercise,
frequently repeated, without cardiac tire while causing the pulse to
be rapid at the time, slows the pulse during the interim of such
exercise and may gradually cause a more or less permanent slow
pulse. It should be remembered that athletes have slow pulse, and
the severity of their condition must not be interpreted by the rate
of the pulse. Even with high fever the pulse of an athlete may be
slow.

Not enough investigations have been made of the rate of the pulse
during sleep under various conditions. Klewitz [Footnote: Klewitz:
Deutsch. Arch. f. klin. Med. 1913, cxii, 38.] found that the average
pulse rate of normal individuals while awake and active was 74 per
minute, but while asleep the average fell to 59 per minute. He found
also that if a state of perfect rest could be obtained during the
waking period, the pulse rate was slowed. This is also true in cases
of compensated cardiac lesions, but it was not true in decompensated
hearts. He found that irregularities such as extrasystoles and
organic tachycardia did not disappear during sleep, whereas
functional tachycardia did.

It is well known that high blood pressure slows the pulse rate; that
low blood pressure generally increases the pulse rate, and that