715 



nodes of Raiivier at tliose nerve fibers in the brain, and with tlie 

 fact that the number of nodes at the |)eripheral nerve fil)er8 remains 

 the same for large and small individnais of the same species, whereas 

 between different s[)ecies this number varies proportionally to the 

 length of the peri[)heral nerve fiber. ') 



The meaning of the term /-'0.28 nmsi l)e looked for in the physio- 

 logical function of the nerve fiber and the retina, namely the con- 

 duction of the impulsions or intlnxions. Likewise of the same rela- 

 tion between the body weight and the volume of the ganglion cell, 

 which volume must undoubtedly be in relation with the quantity 

 of the impulsions which it can receive and emit. 



GÖTHLIN (in 1907) was the first to pronounce the idea that the 

 rate of conduction of the nerve inflnxion in an axis cylindei' seems 

 to be in a definite relation to the diameter of the axis cylinder and 

 to the thickness of the medullary sheath, when he tried to apply 

 William Thomson's cable formulae to the white nerve fiber*). Ten 

 years later Göthlin justly considers the data enabling us to judge 

 about this relation, deiilorably few'). He reminds (in 19J7) of the 

 fact that according to the exceedingly important researches by 

 Chauveau in 1878, the conduction in the motor nerve fibers of 

 the larynx of the Horse is about 8 times more rapid than in the 

 motor nerve fibers of the oesophagus of this animal''), and he brings 

 this difference in rate of conduction of the "influx iierveux"' in 

 connection with the very different thickness of the nerve fibers in 

 cpiestion^). In the very thin and at the same time non-medullated 

 fibers of the splenic nerve of the Ox the rate of conduction, according 



1) A. E. Boycot, On the Number of Nodes of Ranvier in Diffei-ent Stages ofllic 

 Growth of Nerve Fibres in the Frog. Journal of Physiology. Vol. 30 (1904). 

 London, p. 370 — 380. At this place we find also a comparison of Cavia porcellus 

 and Mus musculus. 



-) G. F. Göthlin. Experimenlelia Undersökningar af Ledningens Natur i den 

 Hvita Nervsubstansen. Uppsala 1907, p. 120 seq. 



') Relation entre le fonctionnement et la structure des elements nerveux. Upsala 

 1917, p. 15. 



*) A. Ghauveau, Vitesse de propagation des excitations dans les nerfs moteur» 

 des muscles rouges de faisceaux striés, soustraits a I'empire de la volonté. Comptes 

 rendus de l'Académie des Sciences. Tome 87. Paris 1878, p. 238 — 242. There, 

 p. 138—142, also: Vitesse de propagation des excitafions dans les nerfs moteurs 

 des muscles de la vie animale, chez les animaux mammifères. 



») A. VAN Gehuchten and M. Molhant. (Contribution a l'étude anatomique du 

 nerf pneumogastrique cliez THomme. Le Névraxe, Vol. 13. Lou vain 1912, p. 96) 

 for the Rabbit. 



