exists, lithic concretions take place in the urinary apparatus in the
same manner as sedimentary particles cohere or crystallize elsewhere.
The urine becoming pent up and stagnant while charged with saline
matter, either deposits this around a nucleus introduced into it, or as
a surplus when the menstruum is insufficient to suspend it. The most
depending part of the bladder is that where lithic concretions take
place; and if a sacculus exist here, this, becoming a recipient for the
matter, will favour the formation of stone.] [End Footnote]

FIG. 1, Plate 63.--The lateral lobes of the prostate, 3, 4, are
enlarged, and contract the prostatic canal. Behind them the third lobe
of smaller size occupies the vesical orifice, and completes the
obstruction. The walls of the bladder have hence become fasciculated and
sacculated. One sac, 1, projects from the summit of the bladder;
another, 2, containing a stone, projects laterally. When a stone
occupies a sac, it does not give rise to the usual symptoms as
indicating its presence, nor can it be always detected by the sound.

[Illustration]
Plate 63,--Figure 1.

FIG. 2, Plate 63.--The prostate, 2, 3, is enlarged, and the middle lobe,
2, appears bending the prostatic canal to an almost vertical position,
and obstructing the vesical orifice. The bladder, 1, 1, 1, is thickened;
the ureters, 7, are dilated; and a large sac, 6, 6, projects from the
base of the bladder backwards, and occupies the recto-vesical fossa. The
sac, equal in size to the bladder, communicates with this organ by a
small circular opening, 8, situated between the orifices of the ureters.
The peritonaeum is reflected from the summit of the bladder to that of
the sac. A catheter, 4, appears perforating the third lobe of the
prostate, 2, and entering the sac, 5, through the base of the bladder,
below the opening, 8. In a case of this kind, a catheter occupying the
position 4, 5, would, while voiding the bladder through the sac, make it
seem as if it really traversed the vesical orifice. If a stone occupied
the bladder, the point of the instrument in the sac could not detect it,
whereas, if a stone lay within the sac, the instrument, on striking it
here, would give the impression as if it lay within the bladder.

[Illustration]
Plate 63,--Figure 2.

FIG. 3, Plate 63.--The urethra being strictured, the bladder has become
sacculated. In the bas fond of the bladder appears a circular opening,
2, leading