on
what circumstance, either anatomical or pathological, can one part of
the urethra be more liable to the organic stricture than another?]

Figs. 1 and 2, Plate 59.--In these figures are presented seven forms of
organic stricture occurring, in different parts of the urethra. In a,
Fig. 1, the mucous membrane is thrown into a sharp circular fold, in the
centre of which the canal, appears much contracted; a section of this
stricture appears in b, Fig. 2. In b, Fig. 1, the canal is contracted
laterally by a prominent fold of the mucous membrane at the opposite
side. In c, Fig. 1, an organized band of lymph is stretched across the
canal; this stricture is seen in section in c, Fig. 2. In e, Fig. 1, a
stellate band of organized lymph, attached by pedicles to three sides of
the urethra, divides the canal into three passages. In d, Fig. 1, the
canal is seen to be much contracted towards the left side by a
crescentic fold of the lining membrane projecting from the right. In f,
the canal appears contracted by a circular membrane, perforated in the
centre; a section of which is seen at a, Fig. 2. The form of the organic
stricture varies therefore according to the three following
circumstances:--1st. When lymph becomes effused within the canal upon
the surface of the lining mucous membrane, and contracts adhesions
across the canal. 2ndly. When lymph is effused external to the lining
membrane, and projects this inwards, thereby narrowing the diameter of
the canal. 3rdly. When the outer and inner walls of a part of the
urethra are involved in the effused organizable matter, and on
contracting towards each other, encroach at the same time upon the area
of the canal. This latter state presents the form, which is known as the
old callous tough stricture, extending in many instances for an inch or
more along the canal. In cases where the urethra becomes obstructed by
tough bands of substance, c e, which cross the canal directly, the
points of flexible catheters, especially if these be of slender shape,
are apt to be bent upon the resisting part, and on pressure being
continued, the operator may be led to suppose that the instrument
traverses the stricture, while it is most probably perforating the wall
of the urethra. But in those cases where the diameter of the canal is
circularly contracted, the stricture generally presents a conical
depression in front, which, receiving the point of the instrument,
allows this to enter the central p