So there are combinations of glands to assist or restrain others, or to control a body function, or to determine the domination or abeyance of an instinct. One such has been named the kinetic system because it comes into play in situations which demand prompt adaptation without hesitancy, and a consequent immediate transformation of static or stored energy into kinetic or active energy. According to this conception the brain, the adrenals, the liver, the thyroid and the muscles together constitute a machine very much like an automobile. The self-starter of the machine is the brain, with storage battery (composed of stored past memories) and ignition combined. The thing seen without, or the idea felt within, act as the initial sparks, while the adrenals, as the carburetors, permit the freer flow of fuel, sugar, from the liver. The thyroid works as the accelerator, the original impulse finally landing upon muscles keyed up and supplied with food to meet the situation, be it that of removing a poison, removing an aggressor (attack) or removing the individual himself (running away). When one is exhausted by exertion and emotion, injury, intoxication or infection, it is these members of the kinetic system, the brain, the adrenals, thyroid and liver, which are exhausted. Exhaustion diminishes when the activity of the brain is diminished by anesthetics, and cured when it is abolished by sleep. If the adrenal gland may be called the Gland of Emergency energy, the Kinetic System is entitled to the name of Council of Emergency Defense for the organism. The Kinetic Drive is the name that has been given to the whole system at work. It is one of the best examples we have of inter-glandular co-operations and reactions in reply to the threat of danger or the hint of pleasure. THE CHECK AND DRIVE SYSTEM Another instance of the complexity of these inter-glandular reactions is furnished by the thyroid and the adrenals. The thyroid and the adrenals are mutually stimulating--when the thyroid oversecretes, the adrenal dittos, and vice versa. Yet they have directly opposed effects upon the economy--because they act upon antagonistic portions of the involuntary or vegetative nervous system, the system which is independent of the will. Before proceeding further, it is worth while sketching this division of the nervous system.