46 ROBERT OGDEN AND SHEPHERD IVORY FRANZ 



movement. While it would be too venturesome to say from the 

 experiments on the monkeys that the power of purely " volun- 

 tary" movement was recovered, the experiments on man which 

 have previously been cited, and those which will later be pub- 

 lished, show conclusively that such " voluntary " movements 

 may be produced even though the paralysis has been what 

 neurologists call " residual/ 7 and in some cases even when it has 

 persisted for a decade or more. It is, however, reasonable to 

 suppose that not all of the " recovered" motor ability of the 

 monkeys is of the nature of reflexes of a complicated type, and 

 if we conclude that only a few of the recovered movements are 

 " voluntary" it is sufficient to cause us to hesitate to accept the 

 generally accepted view of cortical motor function. 



Here also may be cited the results which have been reported 

 by von Monakow regarding the pyramidal fibers, for he finds 

 that after the complete destruction of the motor cortex there is 

 approximately from 25 to 33 per cent of the pyramidal fibers 

 intact, or rather undegenerated. This fact would point, as- 

 suming the pyramidal fibers to be purely motor, to the conclu- 

 sion that other parts of the brain normally send impulses to the 

 anterior horn cells, and that the control of the body muscula- 

 ture is not entirely from the so-called precentral region, and it 

 may be not entirely cortical. There remains from this anatom- 

 ical argument the question of " voluntary" and "involuntary" 

 movements, but this is more completely answered by the re- 

 sults of the present series of experiments as well as by the re- 

 sults of the experiments with human paralytics to which refer- 

 ence has been made. 



The results are of interest in another direction, in that they 

 place in the hands of the experimenter the means for the rapid 

 recovery of motor function so that the " vicarious" functions of 

 other cerebral parts may be investigated. If there is a delay 

 in the recovery for periods of six to twelve months the pos- 

 sibilities of experimentation are greatly reduced. With the 

 possibility of producing such rapid recoveries as we have de- 

 scribed in this paper there is opened up the means of investigat- 

 ing certain motor functions which were not feasible previously 



