

506 THE NERVOUS SYSTEM. 



appears also to be propagated to the spinal cord, and thence 

 reflected to the motor nerves supplying the Fallopian tubes. 

 The involuntary action of the uterus in expelling its con- 

 tents during parturition, is also of a purely reflex kind, 

 dependent in part upon the spinal cord, though in part 

 also upon the sympathetic system : its independence of the 

 brain being proved by cases of delivery in paraplegic 

 women, and now more abundantly shown in the use of 

 chloroform. 



Besides these acts regularly performed under the influ- 

 ence of the reflecting power of the spinal cord, others are 

 manifested in accidents, such as the movement of the limbs 

 and other parts to guard the body against the effects of 

 sudden danger. When, for example, a limb is pricked or 

 struck, it is instantly and involuntarily withdrawn from the 

 instrument of injury ; and the same preservative tendency 

 of the reflex power of the cord is shown in the outstretched 

 arms when falling forwards, and their reversed position 

 when falling backwards ; the action, although apparently 

 voluntary, being really, in most cases, only an instance of 

 reflex action. 



To these instances of spinal reflex action, some add yet 

 many more, including nearly all the acts which seem to be 

 performed unconsciously, such as those of walking, running, 

 writing, and the like : for these are really involuntary 

 acts. It is true that at their first performances they are 

 voluntary, that they require education for their perfection, 

 and are at all times so constantly performed in obedience 

 to a mandate of the will, that it is difficult to believe in 

 their essentially involuntary nature. But the will really 

 has only a controlling power over their performance ; it can 

 hasten or stay them, but it has little or nothing to do with 

 the actual carrying out of the effect. And this is proved 

 by the circumstance that these acts can be performed with 

 complete mental abstraction : and, more than this, that the 

 endeavour to carry them out entirely by the exercise of the 



