The first general idea is one that is bound to grow in
importance to you. It is difficult to state this idea in a sen-
tence. What it amounts to is this--a typing signal would be
utterly worthless if it were not for the whole situation is which
you met it.  For the moment this signal stood out as a special
part of the whole incident. Time flashed. Your typing went on.
The situation changed, It will help you to realize that this
signal gad ti be a part of that whole situation if you acknow-
ledge that really you were unaware of any such signal. Probably
you were aware only of the total happenings at that instant of
typewriting. Literally, conditioning crept upon you unawares.
      Why not mull over this general idea while it is reiterated
is somewhat different words for three paragraphs? Usable sig-
nals, is you noticed in the study of even stupid hens, show some
contrast to surroundings. No fragmentary sign can serve as a
signal unless it stands out in definite proportion to these sur-
roundings. Such a signal has to stand out with a defined degree
if nutebsuty. If you are gradually conditioned to select a dark
blue box filled with candy instead of a somewhat lighter blue
box that somehow never contains candy, for example, how should
you later choose between the dark blue box a box of somewhat
darker blue? Naterally, you select the latter, because your con-
ditioning singnal is the ratio--the darker of two bulks.