'._' Till. M:i;\OL'S SYSTEM AND ITS CONSKHVATION 



cr ible units may be thrown into action in a reflex fashion 

 or when the cerebral processes are of an exceptional char- 

 acter, as in stroiii-; emotion, hypnosis, delirium, and the 

 like. These -tales are often occasions for the most aston- 

 ishing display of strength. This is the more surprising 

 because the subjects are not necessarily athletic or even 

 of average muscular development. Surely in the case of a 

 man wasted by fever we have no right to assume a superior 

 condition of the muscles themselves. If such a man sud- 

 denly becomes violent and masters attendants whom he 

 could not handle when in his normal condition, it is most 

 natural to infer that his peculiarity consists in a more 

 complete power to command his limited muscular re- 

 sources than is realized at other times. 



Other possible explanations may, nevertheless, suggest 

 themselves. The capacity of muscles to respond to the 

 stimulation proceeding from the central nervous system 

 depends in part upon local chemical conditions and upon 

 the amount of the blood-pressure. When we shall dis- 

 cuss the physiologic features of emotion we shall emphasize 

 the value to the muscles of the internal secretion known 

 as adrenalin. This is poured out by the adrenal bodies 

 in times of excitement and has a marked effect in t In- 

 direction of reinforcing contraction and postponing fatigue. 

 To adrenalin we may ascribe a share in conferring upon 

 the individual what we recognize as the "strength of 

 de-pcration." Such a chemical adjustment may occur 

 in delirium or under hypnosis. 



In the last-named condition it is a common demon- 

 stration to extend the body of the subject from our chair 

 to another and to seat another person upon him midway 

 between the points of support. The muscles which suc- 

 << fully meet this severe test may be untrained and 

 insignificant in appearance. Is their unexpected rigidity 

 due to chemical alterations in their make-up or to a 

 stimulation of their libers which is much more inclusive 

 than can ordinarily be secured? May not both ela 

 of factors be present at once? 



