18 
DR. PETTIGREW ON THE MUSCULAR ARRANGEMENTS 
the bladder may be divided into several layers, the fibres of the first or most external 
layer having a longitudinal direction, those which come next being inclined on either 
side of the longitudinal one, the succeeding or deepest fibres, which are the most 
oblique, gradually becoming transverse. This author pointed out the important fact 
that the fibres mutually cross each other. 
A. Sabatier* * * § in a recent memoir divides the fibres into a superficial layer of longitu- 
dinal fibres — a deeper layer of oval fibres, a still deeper one of circular or elliptical 
fibres, and a layer of internal or deep longitudinal fibres. The external longitudinal 
fibres, in his opinion, surround the summit of the bladder, and form with those of the 
opposite side a sort of cravat ( cravate ) behind the base of the urachus, other and 
similar fibres passing beneath the neck of the bladder to form an inferior cravat. The 
superficial fibres, as will be observed from this description, are continuous towards the 
apex and base. The oval fibres, he remarks, form loops (arises), which, being trans- 
verse on the anterior surface and oblique on the sides, converge and diverge posteriorly 
to form the italic letter x. The circular or elliptical fibres, according to Sabatier, 
extend from the summit of the bladder to the cervix vesicse and form complete circles ; 
the deep longitudinal or internal ones, which he regards as the internal prolongations 
of the urachus, intersecting the circular fibres at right angles, and being continued into 
the prostatic portion of the urethra. 
Other authors might be cited, as Douglas, Butty, Pearson, Thompson, Sappey, 
Mercier, &c., but the opinions already quoted embrace, as far as I am aware, everything 
at present known of the general arrangement. The sphincter, trigone, and muscles of 
Bell have been described separately and variously. Guthrie^, assisted by Messrs. 
Taylor, Bedford, and Hancock, altogether failed to detect a sphincter for the bladder, 
and came to the conclusion that no circular fibres surround the neck of the organ; 
whereas Eutty J, as early as 1750, speaks of a complete sphincter in the shape of a 
small muscle of circular fibres which invests the neck of the bladder and prevents the 
involuntary emission of the urine. The sphincter vesicse was regarded by Huschke f as 
being less regular and distinct than the internal sphincter of the anus, and Sir Charles 
Bell § describes it as consisting of a semicircular band of fibres about half an inch in 
breadth, and particularly strong on the under surface of the cervix; the fibres of the 
upper portion of the band, which are fewer in number and weaker, dispersing them- 
selves in the substance of the bladder. Sabatier f and Bell f gave it as their belief 
that the trigone and luette are the most sensible parts of the bladder, and Mor- 
* Recherches Anatomiques et Physiologiques sur les Appareils Musculaires Correspondants k la vessie et 
k la prostate dans les deux sexes. Paris, 1864. 
f Op . cit . 
$ A Treatise on the Urinary Passages. By William Rutty, M.D. Lond. 1750. 
§ A Treatise on the Diseases of the Urethra, Vesica Urinaria, Prostate, and Rectum. By Charles Bell. 
3rd edit. With Notes by John Shaw. Lond. 1822. 
