months may still be successfully transplanted on to the body.
(_British Medical Journal_, July 19, 1902.)

Everything indicates, remark Stanley Hall and Donaldson ("Motor
Sensations in the Skin," _Mind_, 1885), that the skin is "not
only the primeval and most reliable source of our knowledge of
the external world or the archæological field of psychology," but
a field in which work may shed light on some of the most
fundamental problems of psychic action. Groos (_Spiele der
Menschen_, pp. 8-16) also deals with the primitive character of
touch sensations.

Touch sensations are without doubt the first of all the sensory
impressions to prove pleasurable. We should, indeed, expect this
from the fact that the skin reflexes have already appeared before
birth, while a pleasurable sensitiveness of the lips is doubtless
a factor in the child's response to the contact of the maternal
nipple. Very early memories of sensory pleasure seem to be
frequently, perhaps most frequently, tactile in character, though
this fact is often disguised in recollection, owing to tactile
impression being vague and diffused; there is thus in Elizabeth
Potwin's "Study of Early Memories" (_Psychological Review_,
November, 1901) no separate group of tactile memories, and the
more elaborate investigation by Colegrove ("Individual Memories,"
_American Journal of Psychology_, January, 1899) yields no
decisive results under this head. See, however, Stanley Hall's
valuable study, "Some Aspects of the Early Sense of Self,"
_American Journal of Psychology_, April, 1898. Külpe has a
discussion of the psychology of cutaneous sensations (_Outlines
of Psychology_ [English translation], pp. 87 et seq.)