assage unerringly. A stricture formed
by a crescentic septum, such as is seen in b d, Fig. 1, offers a more
effectual obstacle to the passage of a catheter than the circular septum
like a f.

[Illustration]
Plate 59.--Figure 1, Figure 2.

Fig. 3, Plate 59.--In this there are seen three separate strictures, a,
b, c, situated in the urethra, anterior to the bulb. In some cases there
are many more strictures (even to the number of six or seven) situated
in various parts of the urethra; and it is observed that when one
stricture exists, other slight tightnesses in different parts of the
canal frequently attend it. (Hunter.) When several strictures occur in
various parts of the urethra, they may occasion as much difficulty in
passing an instrument as if the whole canal between the extreme
constrictions were uniformly narrowed.

[Illustration]
Plate 59.--Figure 3.

Fig. 4, Plate 59.--In this the canal is constricted at the point a,
midway between the bulb and glans. A false passage has been made under
the urethra by an instrument which passed out of the canal at the point
f, anterior to the stricture a, and re-entered the canal at the point c,
anterior to the bulb. When a false passage of this kind happens to be
made, it will become a permanent outlet for the urine, so long as the
stricture remains. For it can be of no avail that we avoid re-opening
the anterior perforation by the catheter, so long as the urine prevented
from flowing by the natural canal enters the posterior perforation.
Measures should be at once taken to remove the stricture.

[Illustration]
Plate 59.--Figure 4.

Fig. 5, Plate 59.--The stricture a appears midway between the bulb and
glans, the area of the passage through the stricture being sufficient
only to admit a bristle to pass. It would seem almost impossible to pass
a catheter through a stricture so close as this, unless by a laceration
of the part, combined with dilatation.

[Illustration]
Plate 59.--Figure 5.

Fig. 6, Plate 59.--Two instruments, a, b, have made false passages
beneath the mucous membrane, in a case where no stricture at all
existed. The resistance which the instruments encountered in passing out
of the canal having been mistaken, no doubt, for that of passing through
a close stricture.

[Illustration]
Plate 59.--Figure 6.

Fig. 7, Plate 59.--A bougie, b b, is seen to perforate the urethra
anterior to the stricture c, situated an inch behind the gla