496 BIOLOGICAL PHYSICS 



ears, which may be regarded as deriving their lymph 

 supplies principally from cerebro-spinal sources, supple- 

 menting them when and where necessary from the 

 adjacent blood circulation through its liquor sanguinis, 

 and expending them in a regulated outflow, all which 

 is accompanied by a regulated escape of caloric and 

 consequent steady maintenance of the body temperature. 



Circulation in its widest sense we thus realise embraces 

 every variety of circulation, material and dynamic, which 

 has been observed in action throughout the living fabric 

 of the body, and constitutes at once an almost ever ready 

 and available means of maintaining the temperature of 

 that body at a constant degree we say, almost ever 

 ready and available, because occasionally there occur 

 intervals of disturbance when morbid influences are at 

 work begetting pathological elevations, or depressions of 

 temperature, according as the means of escape, or 

 imprisonment, of caloric are provided, and according to 

 the extent to which the powers of natural adjustment 

 have been affected. 



Amongst the circulations referred to, as operative in 

 the regulation of body temperature, we must include 

 the circulation of energy, chemical, vital, nerve and 

 caloric, in fact, all forms of force involved in and flowing 

 from functional activity. 



By these various means of upholding and sustaining 

 a regular, or mean, temperature, the living body has at 

 its disposal an "array of choice," so to speak, of a 

 very complete and varied character, by which the vis 

 medicatrix nature is enabled successfully to assert her 

 powers amid the most changeful surroundings. The 

 increase or decrease of body temperature beyond the 

 degree of 98-4 F. is most jealously regarded by nature, 

 and the requisite means of adjustment being almost 

 always available she is almost constantly able to main- 

 tain the requisite equilibrium ; but if perchance an accident 

 occurs to modify, or destroy, these means, she, if the life 

 be still sustained, begins along the lines of action still 

 remaining to her to remove the effects of the accident 

 with its consequent " wreckage," and to effect the work 

 of the readjustment of these means and the restoration 



