is, for several
weeks.

It cannot be emphasised too strongly that the induration of the primary
lesion, which has obtained for it the name of "hard chancre," is its
most important characteristic. It is best appreciated when the sore is
grasped from side to side between the finger and thumb. The sensation on
grasping it has been aptly compared to that imparted by a nodule of
cartilage, or by a button felt through a layer of cloth. The evidence
obtained by touch is more valuable than that obtained by inspection, a
fact which is made use of in the recognition of _concealed
chancres_--that is, those which are hidden by a tight prepuce. The
induration is due not only to the dense packing of the connective-tissue
spaces with lymphocytes and plasma cells, but also to the formation of
new connective-tissue elements. It is most marked in chancres situated
in the furrow between the glans and the prepuce.

_In the male_, the primary lesion specially affects certain
_situations_, and the appearances vary with these: (1) On the inner
aspect of the prepuce, and in the fold between the prepuce and the
glans; in the latter situation the induration imparts a "collar-like"
rigidity to the prepuce, which is most apparent when it is rolled back
over the corona. (2) At the orifice of the prepuce the primary lesion
assumes the form of multiple linear ulcers or fissures, and as each of
these is attended with infiltration, the prepuce cannot be pulled
back--a condition known as _syphilitic phimosis_. (3) On the glans penis
the infiltration may be so superficial that it resembles a layer of
parchment, but if it invades the cavernous tissue there is a dense mass
of induration. (4) On the external aspect of the prepuce or on the skin
of the penis itself. (5) At either end of the torn fraenum, in the form
of a diamond-shaped ulcer raised above the surroundings. (6) In relation
to the meatus and canal of the urethra, in either of which situations
the swelling and induration may lead to narrowing of the urethra, so
that the urine is passed with pain and difficulty and in a minute
stream; stricture results only in the exceptional cases in which the
chancre has ulcerated and caused destruction of tissue. A chancre within
the orifice of the urethra is rare, and, being concealed from view, it
can only be recognised by the discharge from the meatus and by the
induration felt between the finger and thumb on palpating the urethra.

_In the female_, the