te by
it. Another will throw out its secretion in order to neutralize the
effects produced. Or its own activity will be depressed or completely
inhibited by it. Thus the pituitary arouses the interstitial glands
and vice versa, whereas the pancreas and the thyroid are mutually
inhibitory. Indeed, whole systems of glands may work in unison, or be
pitted against each other in certain situations, especially when
the organism is subjected to conflicting impulses with the clash
of opposing instincts, like fear and anger. In general there is
reciprocity and team work among the internal secretions.

A certain minimum amount of each must be present if life is to
continue along the normal lines. Whether there is to be an excess
of any one secretion above this minimum, or a deficiency below it,
decides the fate of the individual. If there is deficiency of one, the
other members of the directorate attempt to make up for what has been
lost, and to carry on its work by an extra effort, to substitute. Or,
released from the discipline of the deficient member, or the necessity
for antagonizing it, they may be released from its stimulus to
secrete, and produce less of their own specific secretion. A general
reaction all along the line will accompany overaction, oversecretion,
of one gland. Due to consequent stimulations and depressions of
other glands, some may be excited by the event to overwork--some to
assist--others, to act as antidote for--the excess secretion, while
still others, relieved of a burden, do not have to supply as much of
their quota under the circumstances and so shut down, or limit their
output.

It is important to get clearly in mind these subtle inter-reactions of
the different ductless glands. They may be antagonistic in their end
effects because of the opposed functions of the nerves or organs
stimulated. There are inhibitions and restraints produced when a gland
will send out its secretions to stop another gland secreting. There
are compensations resulting when because of insufficiency of a gland,
others will endeavour, by manufacturing more of their own secretion,
to compensate for the loss. There are mutual co-operations,
partnerships, when a gland will oversecrete to assist another, or in
response to another which is also oversecreting. There are losses
of balance, so that when one gland ceases secreting, another will
simultaneously or soon after. Normal secretion, oversecretion or
undersecretion are thus