the paternal and half from the maternal
side.

=Heredity. The Mneme.=--The secret of heredity lies in the phenomena
which have been just described. Hereditary influence preserves all its
primary power and original qualities in the chromosomes, which enlarge
and divide, while the vitelline substance, absorbed by the chromosomes
and transformed by the vital chemical processes into the specific
substance of the chromosomes, loses its specific and plastic vital
energy, as completely as the food which we swallow loses its energy in
forming the structure of our living organs. We do not acquire any of
the characters of the ox by eating beefsteaks; and the spermatozoid,
after eating much vitelline protoplasm, preserves its own hereditary
energies, increased and fortified, but without change in their
qualities.

In this way the nuclear chromatin of our germinal cells becomes the
carrier of all the hereditary qualities of the species (hereditary
mneme), and more especially those of our direct ancestors. The
uniformity of the intracellular phenomena in cell division and
conjugation proves, however, that, without being capable of
reproducing the individual, the other non-germinal cells of the body
may also possess these hereditary energies, and that there exists,
hidden behind all these facts, an unknown law of life, the explanation
of which is reserved for the future.

However, a recent work based on an idea of the physiologist, _E.
Hering_, which looks upon instinct as a kind of memory of the species,
opens up a new horizon. I refer to the book of _Richard Semon_: "The
_mneme_ considered as the conservative principle in the transmutations
of organic life." (_Die Mneme als erhaltendes Prinzip im Wechsel des
organischen Geschehens_, Leipzig, 1904.)

_Conception of Irritation._[1]--By the aid of the fundamental facts of
morphological science, biological and psychological, _Semon_ proves
that _Hering's_ idea is more than an analogy, and that there is a
fundamental identity in the mechanism of organic life. In order to
avoid the terminology of psychology which tends to be equivocal,
_Semon_ employs some new terms to designate his new ideas, based on
the fundamental conception of _irritation_ in its physiological sense.

_Semon_ defines _irritation_ as an energetic action on the organism
which determines a series of complicated changes in the irritable
substance of the living organism. The condition of the organism thus
modified