PROF. LIONEL §. BEALE, F.R.C.P., F.R.S., ON VITALITY. 63 
life. The organ which I think is most suitable is the heart. 
Consider for a moment how very interesting and important 
are the changes which take place from moment to moment 
in the heart, in every part of the muscular substance of the 
heart, which is continuous sly at work from before birth to old 
age and death. The alternate shortening and lengthening 
of the muscular fibres never stops for many seconds. The 
heart never rests. The nerve cells and the gangla which 
govern its action and determine the healthy regularity of its 
beats never sleep. The sustained action of the heart, and 
as I venture to think of all muscular tissue, is indirectly de- 
pendent on the living matter of the muscular fibres and that 
of the nerves and eanglia connected with it. But I dare say 
this view will be contradicted, though probably not in print. 
I should like those who differ from me to state the ground of 
their objection. All muscles and all kinds of muscular tissue 
are everywhere supplied with nerves. There are nerve 
ganglia in the heart itself, by which the activity, regularity, 
and equality of the muscular contraction in its several parts is 
provided for. Remember that the heart is not the only one of 
our organs which never rests and never goes to sleep during 
life. Its “nutrition” proceeds without interruption, and the 
perpetual removal of the products of decay are provided for 
by a number of complex changes which do not cease durmg 
life, and our health and strength and working power are 
maintained and longevity rendered possible. On the other 
hand the muscles of the limbs and body generally do 
require rest, and if worked too hard become tired, and then 
rest for a time becomes imperative. The heart continues to 
beat perhaps sixty or more times a minute, perhaps nine or 
ten million beats m a year. Many of us in this room now 
have experienced many millions of beats since our heart 
was first formed, hardly conscious of the necessary and 
wonderful work incessantly going on in our body. But 
the wonder is increased if we consider the a of the 
formation which proceed early in life, for while its work 
goes on in the early years, at the same time that the heart 
continues to 4 grow. The heart is one of the first organs that 
performs actual work in the organism. In the chick the 
heart and corresponding part of the nervous system are 
formed very early in the period of incubation. In a few 
days, and in the eggs of small birds probably within forty- 
eight hours of the egg being laid, there would be indications 
of the heart, and not only so, but the red blood is at the 
