222 MUSCULAR SYSTEM. 



Q. What vital property is exclusively seated in the 

 muscular system of animal life? 



JL. Animal contractility, on which depend locomotion 

 and the voice. 

 ' Q. In what does this animal contractility consist? 



ft.. In the faculty of moving under cerebral influence, 

 whether this influence is produced by the will, or any 

 other cause. 



Q. In what general character do the vital properties of 

 animal life differ from those of organic life? 



ft. In this; that the exercise of the properties of or- 

 ganic life is concentrated in the organs, while the exer- 

 cise of those of animal life depend on the organ, the brain, 

 and the nerves. 



Q. How do you prove the brain thus essentially con- 

 nected with the muscular system? 



ft.. Causes which increase the energy of the brain have 

 that effect on the muscles, and those which diminish that 

 energy, debilitate the muscles. 



Q. In what forms are sudden and powerful impres- 

 sions on the brain manifested in the muscular system of 

 animal life? 



ft. As in convulsions and palsy. Indeed this muscular 

 system indicates the condition of the brain. The muscles 

 are to the brain what the arteries are to the heart. 



Q. What three great functions have their seatinthe brain? 



ft.. Perception, voluntary motion, and intellect. These 

 may be separately or entirely destroyed or affected. 



Q. There are two circumstances whicli influence the 

 cerebral power over the muscles, what are they ? 



ft.. The disposition of the nerves to convey this power, 

 and that of the muscles to receive it. 



