Wakming Up. 27 



2. Warming up is not gained with electric stimulation, 

 while it is gained, in those who show the phenomenon, by 

 voluntary effort. 



8. A bloodless arm fatigues at the same rate as a normal 

 arm, and some recovery or warming up is possible even then. 



•4. This warming up may be gained from mental activity 

 and the effect of it shown in a muscle. It seems justifiable, 

 then, to locate the warming up in the brain cells. 



Now, what happens in the cortex to produce this phenome- 

 non? Four causes are suggested. 



1. Tlie use of a center may react on the local arteries and 

 increase the blood supply and nourishment of the nerve cells. 

 This is called hypememia. 



2. The stimulus may spread and involve a much larger 

 area. The automatic motor impulses which may be seen to 

 accompany any vigorous effort or new motion, may be 

 gathered and sent along these active channels. 



3. The nerve cells may discharge more vigorously when 

 excited by products caused by the previous activity. That 

 is, it may be a case of auto-intoxication. 



4. The amoeboid motion of the nerve cells as explained by 

 Golgi, Ramon y Cajal, Krapotkin and others, best explains 

 this warming up. According to them the dendrites, or tree- 

 like branches of the nerves, which arise from the central end 

 of the nerve cell, tend to ball up or contract, when at rest, in 

 sleep, etc. When some stimulus is given, these expand and 

 make connections with their neighbors, and whole areas are 

 thus harnessed for activity which do not respond ordinarily. 



In conclusion a few observations might be suggested. 

 Orators, athletes, students and working men often are aware 

 of this effect and practice mental or physical gymnastics, or 

 both, when about to make an unusual effort. Some orators 

 • always excite themselves by recitation of thrilling literature 

 and by physical efforts before meeting an audience. The 

 effect is important on those who are influenced thus. It 

 means, if we take the fourth explanation above, that larger 

 areas of the brain are brought into activity. The question 



