A MECHANICO-PHYSIOLOGICAL THEORY OF ORGANIC EVOLUTION

Certain organic compounds, among them albumen, are neither

soluble, despite their great affinity for water, nor are they fusible,

and hence are produced in the micellar form. These compounds are

formed in water, where the molecules that arise immediately

adjoining each other arrange themselves into incipient crystals, or

micellæ. Only such of the molecules as are formed subsequently and

come in contact with a micella contribute to its increase in size,

while the others, on account of their insolubility, produce new

micellæ. For this reason the micellæ remain so small that they are

invisible, even with the microscope.

On account of their great affinity for water the micellæ surround

themselves with a thick film of it. The attraction of these micellæ for

matter of their own kind is felt outside this film. Hence the micellæ

with their films unite themselves into solid masses permeated with

water, unless other forces overcome attraction and re-establish a

micellar solution (as in albumen, glue, gum), where the slightly

moving micellæ show a tendency to cling together in chain-like and

other aggregations. Very often there are found, especially in

albumen, half liquid modifications intermediate in fluidity between

the solid masses and the micellar solution.