, which lasts as long as the irritation, is called by _Semon_
the _state of irritation_. Before the action of irritation, the
organism is in a condition which _Semon_ calls the _primary state of
indifference_, and after its action, in the _secondary state of
indifference_.

_Engram. Ecphoria._--If, when an irritation has entirely ceased, the
irritable substance of the living organism becomes modified
permanently during its secondary state of indifference, _Semon_ calls
the action _engraphic_. To the modification itself he gives the word
_engram_. The sum of the hereditary and individual engrams thus
produced in a living organism is designated by the term _mneme_.
_Semon_ gives the name _ecphoria_ to the revival of the engram by the
repetition of part only of the original irritation, or by the entire
but weakened reproduction of the whole state of irritation of the
organism, which was originally produced in a synchronous manner with
the primary irritation.

Thus, an engram may be ecphoriated (that is to say, reproduced or
revived) by the return of one part of the complex of primary
irritations which produced it. A young dog, for example, is attacked
by urchins who throw stones at it. It experiences two kinds of
irritation: (1) the urchins stooping down and throwing stones (optic
irritation); (2) the pain caused by the stones (tactile irritation).

In its brain are produced two associated series of corresponding
engrams. Previously, this dog did not react when it saw people stoop
down. From this moment it will run away and howl at the sight, without
any stone being thrown at it. Thus the tactile engram will be
ecphoriated by the repetition of the original associated irritation.
In the same way, the image of a tree in a known landscape will
ecphoriate the entire landscape.

Moreover, an engram may be revived by the enfeebled return of the
primary irritating agent which produced it, or by an analogous
enfeebled irritation. Thus, the sight of a photograph will revive the
image of a known person. A certain kind of maize imported for a long
time into Norway and influenced in that country during many
generations by the sun of the long summer days, finally accelerated
its time of maturation. When imported again to the south of Europe it
first preserved its faculty of accelerated maturation in spite of the
shortness of the days (_Schuebeler_). _Semon_ gives a series of
analogous examples which show how engrams repeated durin