FREEMAN, W. J. 
the body temperature from studies of clinical thermometry instigated 
by Karl Wunderlich of patterns of temperature change in normal 
cycles and disease. The early workers were impressed by the 
stability of body temperature, and they introduced three concepts 
into temperature regulation which have persisted to the present day. 
One of these was the placing of a line on the clinical thermometer 
at 98.6 F (37 C), which implies a higher degree of constancy of 
body temperature than is actually the case. The second was the 
notion that each of the components of thermoregulatory responses 
was represented by a group of cells in the nervous system, to which 
was given the name "center." The third was that this collection of 
centers was under the control of a master center described as a 
thermostat. Initially, this thermostat was placed in the medulla, 
and only following work by Isenschmidt and Krehl and others at the 
turn of the century was it placed in the hypothalamus. Much of the 
history of temperature regulation since that time has consisted of 
the attempt to define the location and properties of these centers. 
In reality, this has only been part of a much broader application 
of the same principles to other parts of the brain, with particular 
attention devoted to parcelation of function in the cortex and the 
medulla. In some respects this doctrine seems to have been higjily 
successful, notably in the cases of the "respiratory centers" in the 
medulla and the "feeding centers" in the hypothalamus. In other 
instances such as the "speech center" in the parietal cortex, the 
"sleep center" in the thalamus, or the "vasomotor center" in the 
medulla, identification at first seemed adequate and now has been 
brought into question. In the case of temperature regulation, with 
the exception of the so-called "heat center" in the hypothalamus 
(which actually turned out to be a sensory mechanism), the best 
that can be said after nearly a century of hard work is that efforts 
continue. 
In view of the large amount of work based on this doctrine and 
the still continuing doubts as to its validity, one is led to ask how it 
came into existence in the first place and what the underlying 
assumptions for it have been. This doctrine represents in essence 
an attempt to subdivide the brain into its physiological components 
or parts. There were at least three other methods for subdividing 
the brain introduced in the last one hundred years, each to a large 
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