266 Cc. U. ARIENS KAPPERS 
cal study of their relation showed most clearly that the same 
law of neurobiotaxis, the simultaneous relationship in their 
stimulative function, had been the cause of their final arrange- 
ment.® So I was able to formulate the phenomena of neuro- 
biotaxis in the following words: 
I. If in the nervous system several stimulation-charges occur, 
the growth of the chief dendrite, and eventually the displace- 
Centre 
Whence the sti- 
mult 
proceed 
Axiscylinder 
B 
Fig. 3 Showing that, while the axis-eylinder runs with the direction of the 
nervous current, the dendritic outgrowth and the final shifting of the cell body 
occur against the nervous current. A, giant dendrites grown out towards the 
center cf stimulation. B, the cell body (perikaryon) has shifted toward the 
center of stimulation; the axis-cylinder is consequently elongated. 
ment of the cell-body itself, takes place in the direction, whence 
the majority of stimuli proceed to the cell. 
II. Only between correlated centers does this outgrowth or 
shifting take place. 
III]. The growth of the axis-cylinder (.e., its final connec- 
tion) is not primarily regulated by motor centers,!? but also here 
synchronic or successive stimulation (correlation) acts a part." 
"Folia Neurobiologica, Bd. 1, 1908. 
10 Not by some undefined transcendental willing (teleologically). 
11 That is, it is defined by correlation. 
