Myelin figures which grow from a floating egg-yolk lecithin lump on a surfa
ce of water/glycerin mixture have been found to grow only vertically toward
s the bottom of a glass cell and never to grow horizontally along the mediu
m surface nor radially. The structure of the growing myelin figures is basi
cally simple rod-like or a bundle of a few simple rods. Helixing, twisting
or coiling myelin figures were never observed under the present experimenta
Taking the results obtained from the reported growth behaviour of myelin fi
gures into consideration, it is proposed that one of the driving forces of
helixing, coiling and twisting growth of myelin figures is thought to be du
e to a chemical potential difference caused by a concentration gradient alo
ng the radial direction perpendicular to the long axis of a myelin figure.
The hydrocarbon chains in the fully hydrated stacked bilayer of myelin figu
res are proposed to be in a more ordered state than reported so far. The ar
rangement of hydrocarbon chains, both in myelin figures and in an egg-yolk
lecithin/water complex, and the density of them also will be discussed.