re being divided should be regulated by the operator himself.
If he requires the perinaeum to be protruded and the urethra directed
towards the place of the incision, he can effect this by depressing the
handle of the instrument a little towards the right groin, taking care
at the same time that the point is kept beyond the prostate in the
interior of the bladder.

DESCRIPTION OF THE FIGURES OF PLATES 52 & 53.

PLATE 52.

FIGURE 1.

A. The urethra.

B. Accelerator urinae muscle.

C. Central perinaeal tendon.

D D. Right and left erector penis muscle.

E E. The transverse muscles.

F. The anus.

G G. The ischiatic tuberosities.

H. The coccyx.

I I. The glutei muscles.

K K. The levator ani muscle.

L. The left artery of the bulb.

[Illustration: Abdomen, showing blood vessels and other internal organs.]
Plate 52.--Figure 1

FIGURE 2.

A, D, F, G, H, I, K, L refer to the same parts as in Fig. 1, Plate 52.

B. The urethra.

C. Cowper's glands between the two layers of--

E. The deep perinaeal fascia.

M. The bulb of the urethra.

[Illustration: Abdomen, showing blood vessels and other internal organs.]
Plate 52.--Figure 2

PLATE 53.

FIGURE 1.

A, B, C, E, F, G, H, I, K, L refer to the same parts as in Fig. 2, Plate
52.

D D. The two crura penis.

M. The urethra in section

N N. The rectum.

O. The sacro-sciatic ligament.

[Illustration: Abdomen, showing blood vessels and other internal organs.]
Plate 53.--Figure 1

FIGURE 2.

A, B, D, G, H, I, K, L, O refer to the same parts as in Fig. 1, Plate 53.

C C. The two lobes of the prostate.

F. The rectum turned down.

M. The membranous part of the urethra.

N N. The vesiculae seminales.

P. The base of the bladder.

Q Q. The two vasa deferentia.

[Illustration: Abdomen, showing blood vessels and other internal organs.]
Plate 53.--Figure 2.

COMMENTARY ON PLATES 54, 55, & 56.

THE SURGICAL DISSECTION OF THE MALE BLADDER AND URETHRA.--
LATERAL AND BILATERAL LITHOTOMY COMPARED.

Having examined the surgical relations of the bladder and adjacent
structures, in reference to the lateral operation of lithotomy, it
remains to reconsider these same parts as they are concerned in the
bilateral operation and in catheterism.

Fig. 1, Plate 54, represents the normal relations of the more important
parts concerned in lithotomy as performed at the perinaeal region. The
median line, AA, drawn from the symphy