LIFE: ITS ORIGIN AND NATURE 31 
is doubtless some truth in these views, but it 
is probable that such a theory is an extreme 
view of the case, and that such a theory must 
necessarily be modified by later research. This 
interpretation is, of course, in line with a purely 
mechanistic conception of life, and will either 
stand or fall with it. 
The other controller, or regulatng mechanism, 
of the human body is the nervous system , our 
knowledge of which is much older. It may 
roughly be divided into various sub-divisions. 
There are: (a) the “cerebrum,” or brain proper, 
which is the recipient of our sense impressions, 
the originator of many conscious motor im¬ 
pulses, and the seat, apparently, of association 
and consciousness. Behind and below this 
complicated organ, there is the “cerebellum,” 
which is a regulating mechanism, and serves 
to coordinate our movements. Below this, 
again, is the “spinal cord,” with its pairs of 
branching nerves, sensory and motor (i. e., 
nerves of sensation, and nerves of action) 
which largely control the activities of the body. 
In addition to this entire so-called “cerebro¬ 
spinal” system, there is also the “sympathetic” 
nervous system, which controls, very largely, 
the internal activities or functions of the 
various bodily organs—digestion, circulation, 
etc. By means of these mechanisms, which are 
interacting, and influence and control one an¬ 
other, the entire activites of the body are car¬ 
ried on in what appears to us an automatic 
manner, so that the mind is left entirely free 
to conduct, unhampered, the operations of con¬ 
sciousness. 
