680 
Besides it appears that it is the nucleus of the ganglion cell, the 
neurokinete, that controls the mechanism of the neurone, of the nervous 
system, and indeed that of the entire animal organism. The sixth 
power of the volume of the nucleus varies then proportionally as 
the body weight, or the square of the nucleus-volume proportionally 
as the length of the body; thus also the sixth power and the square 
of the velocity of the movement of the anions in the cytoplasm 
and the axone. ; 
Airy *) knew only one instance in physical science in which the 
sixth power came really into application: if the velocity of a sea- 
current (or a river) be doubled, it will carry stones, pushing them 
on along the bottom, of sixty-four times the weight of those (having 
the same shape) carried before. In the animate world the sixth 
power plays a very important part. SUTHERLAND *) found that the 
body weights of all bird species are proportional to the sixth power 
of their brooding-times; those of mutually allied mammals to the 
sixth power of their times of gestation; thus the body lengths of 
the adult animals being proportional to the squares of these times. 
In all these cases, just as in the case treated here, we have to do 
with movement of, or relative to bodies having the same form. 
Hence that cytoplastic metabolism, like this functional metabolism 
of the neurone, is mechanically determined, and the general oceur- 
rence of quantitative relations between nucleus and plasm *) is only 
the consequence of the mechanical relation in the dependence of 
these cell-elements on each other. 
1) G. B. Amy in Minutes of Proceedings of the Institution of Civil Engineers. 
Vol. XXIII. Session 1863—64. London 1864, p. 227. 
2) ALEXANDER SUTHERLAND, Some Quantitative Laws of Incubation and Gestation. 
Proceedings of the Royal Society of Victoria. Vol. VII, (New Series). 1895, p. 270—286. 
3) Compare the researches and studies of: J. J. Gurassimow in Zeitschrift für 
allgemeine Physiologie. Bd. 1. 1992, p. 220—258, — Tu. Boveri in Verhandlun- 
gen der Physikalisch-medicinischen Gesellschaft zu Würzburg. Neue Folge. Band 
35. 1903, p. 67—88, — R. Hertwie in Biologisches Centralblatt. Bd. 23, 1903, 
p. 49—62 and 108—119, — Auge. Pürrer, Vergleichende Physiologie. Jena 1911, 
p. 32 et seq. 
