ons, and midbrain (through
the cell-bodies, fiber terminations, and short neurons which they contain)
completes the reflex action pathways between the surface of the body and
the voluntary muscles, and also between the surface of the body and the
organs of circulation and digestion.

3. The white matter of the spinal cord, bulb, pons, and midbrain (by means
of the fibers of which they are largely composed) forms connections with,
and passes impulses between, the various parts of the central nervous
system.

4. The bulb, because of certain special reflex-action pathways completed
through it, is the portion of the central nervous system concerned in the
control of respiration, circulation, and the secretion of liquids.

*Work of the Sympathetic Ganglia and Nerves.*--The neurons which form these
ganglia aid in controlling the vital processes, especially digestion and
circulation. These neurons are controlled for the most part by fibers from
the bulb and spinal cord, and cannot for this reason be looked upon as
forming an independent system. Their chief purpose seems to be that of
spreading the influence of neurons from the central system over a wider
area than they would otherwise reach. For example, a single neuron passing
out from the spinal cord may, by terminating in a sympathetic ganglion,
stimulate a large number of neurons, each of which will in turn stimulate
the cells of muscles or of glands. Because of this function, the
sympathetic neurons are sometimes called _distributing_ neurons.

*Functions of the Cerebellum.*--Efforts to discover some _special_ function
of the cerebellum have been in the main unsuccessful. Its removal from
animals, instead of producing definite results, usually interferes in a
mild way with a number of activities. The most noticeable results are a
general weakness of the muscles and an inability on the part of the animal
to balance itself. This and other facts, including the manner of its
connection with other parts of the nervous system, have led to the belief
that the cerebellum is the chief organ for the _reflex_ cooerdination of
muscular movements, especially those having to do with the balancing of
the body. In this connection it is subordinate to and under the control of
the cerebrum. Of the relations which the cerebellum sustains to the
cerebrum and to the different parts of the body, the following view is
quite generally held:

In the development of secondary reflexes, as alrea