24

climate do not exhibit, even in the hot, moist atmosphere of Calcutta, such a
low average blood pressure as is seen in the Bengali. As would be expected,
the vasomotor system becomes more or less accustomed to the new conditions
and regains its function of maintaining the tonicity of the vessels in the area
of peripheral resistance; this in its turn is one of the principal factors in the
maintenance of blood-pressure. In the consideration of this question the force
and frequency of the heart-beat is a factor that cannot be neglected. In the
second part of this paper we shall have evidence to bring forward regarding the
physical development of the Bengali and his power of muscular exertion which
will tend to show that the capacity for muscular work is decidedly superior in
the European.

      From a similar line of argument we hold that the same causes that effect
the superiority of the European's ordinary voluntary muscles also maintain the
muscular tissue of the heart in a higher state of nutrition and permit of the
superior force and vigour of its contraction.

      Whatever the cause or causes may be, the pressure of the blood in the
arteries of Bengalis is from 15 per cent. to 22 per cent. lower than in Europeans.
It is worth recalling in connection with this that the percentage of hæmoglobin
is also only about 75 per cent. to 80 per cent. of the European standard.

      To a consideration of this subject we shall return later; at present, we
may close our investigations on the blood of the Bengali by collecting the results
in the form of a table comparing them with normal European standards.

Table IX.