5o8 C. M. Child. 



body. In consequence of these connections complex series of 

 movements and other functional activities which we designate as 

 coordinated are possible. The more complete the system the 

 more perfect the coordination and vice versa. When parts are 

 removed the functional activities of the remaining parts determine 

 what shall regenerate in place of the absent parts; these functional 

 activities being dependent upon the nervous system an apparent 

 correlation between parts of the nervous system and the character 

 of regeneration exists. I see no necessity, however, for assuming 

 the existence of special formative stimuli in this case; further 

 discussion may be postponed to another time. 



As regards the question of "centers" in the nervous system my 

 views are in essential agreement with those of Loeb ('99). The 

 experiments do not indicate the existence of special "centers" in 

 the old sense in the nervous system. I have pointed out, however, 

 that the complexity of behavior seems to be determined in some 

 degree by the amount of the nervous tissue present. In this 

 respect the cephalic ganglia and the longitudinal cords differ 

 greatly in importance. In general the greater the portion of the 

 longitudinal cords remaining intact the more complex and co- 

 ordinated is the character of the activity. But even when the 

 cords are intact throughout the activity is far below the normal 

 activity in complexity and degree of coordination. With the 

 addition of a part of the tissue of the cephalic ganglia to the longi- 

 tudinal cords there is a marked increase in the complexity and 

 coordination of movement, and when half or more of the gang- 

 lionic tissue is present the behavior approaches that of the normal 

 animal. On the other hand after complete rernoval of the cords 

 and half or less of the ganglionic tissue the behavior is almost 

 normal, but when more than half of the ganglionic tissue is absent 

 the complexity of behavior falls to a low level. Moreover, as far 

 as I can determine, it makes no difference whether the part re- 

 moved be anterior, posterior or lateral; it is primarily the amount 

 not the particular region that determines the result. These facts 

 are of importance as indicating that the nervous system is funda- 

 mentally a system of connections permitting the transference and 

 doubtless also the accumulation and transformation of stimuli, 



