will gradually be obliterated as the bladder becomes distended with urine.

It is difficult to make a satisfactory comparison between the position of the bladder in these two cases, and that which it occupies under similar conditions in the adult, on account of its usual position in the latter not having been determined. Almost all the mesial sections of the adult male pelvis that have been published are from cases in which the bladder was more or less distended. Jarjavay,1 plate vi., gives a section with the bladder empty and contracted, in which it is lower in the pelvis than in my specimens; but it looks very much as though it had been allowed to fall downwards and backwards before it was drawn.

Position of Distended Bladder.—The positions and relations of a distended bladder are seen in Fig. 2, which represents a section of a child about six years old. The whole trunk was divided by a mesial section. Before freezing about two ounces of water was slowly injected into the bladder. A comparison of the two specimens demonstrates clearly that the bladder has not only risen into the abdomen, but has also pushed its way down towards the perinæum, and that this has been accompanied by a marked shortening of the length of the prostatic portion of the urethra. This was 7 mm. in length as compared with 13 mm. in the other case. The vesical orifice of the urethra was 10 mm. above the

lowest part of the bulbous portion of the urethra, while in the specimen with the bladder empty it was 20 mm. Again the distance of the urethral orifice from the anus in Fig. 1 was 4 cm., in Fig. 2 about 3 cm. The peritoneum was reflected from the abdominal wall on to the bladder 8 mm. above the pubic symphysis, and the very deep recto-vesical pouch reached to within 18 mm. of the anus. In this child the lower half of this pouch was occupied by serous fluid.

In another male child, about five years old, I injected three ounces of water into the bladder before freezing. In this case the descent of the bladder towards the perinæum, and the shortening of the prostatic part of the urethra, although distinct, was not so marked as in the former case. The length of the prostatic part of the urethra was 10 mm., and the internal orifice of the urethra was 17 mm. above the level of the lowest part of the bulbous portion of the urethra. There was a marked difference in the position of the part of the bladder lying behind the urethral orifice in the two cases with the bladder distended. In the one represented in Fig. 2, this part of the bladder wall passed nearly horizontally backwards for about 2 cm. before it began to turn upwards. In the other case the lower end of the bladder was not so large, and the part behind the urethral orifice passed directly upwards and backwards. In this case the bladder reached as high as the base of the sacrum. The peritoneum was reflected from the anterior abdominal wall on to the

1 Op. cit.

bladder 2.7 cm. above the symphysis pubis. The lower end of the recto-vesical pouch of peritoneum was much higher than in the other case, being 4.3 cm. above the anus.

With regard to the differences in position of the two distended bladders, I think it may be partly attributed to variations in the shape and position of the coccyx. In the specimen shown in Fig. 2 the coccyx is directed downwards and slightly backwards, while in the other specimen it curved somewhat forwards. In the latter case it would give more support to the posterior part of the pelvic floor. As the bladder is gradually distended it will naturally tend to extend in the direction of least resistance, and the descent of the fundus of the bladder in the one case may have been due to a weakness of the pelvic floor.

Garson investigated, in the Anatomical Institute at Leipzig, the "Displacement of the Bladder and Peritoneum in the Male by Distension of the Rectum." He showed that by distension of the rectum the bladder was pushed up towards the abdomen, the prostatic and membranous portions of the urethra being stretched, the former to about double its normal length. Since then several surgeons (Petersen, Ferrier, etc.) have advocated and employed distension of the rectum in order to raise the bladder before performing supra-pubic lithotomy. We usually think of the bladder during distension as simply rising into the abdomen, and but little attention appears to have been paid to the possibility of its passing also towards the perinæum and diminishing the length of the prostatic part of the urethra. The only reference to this subject that I have noticed in anatomical works is in Rüdinger's Supplement zur Topographisch-chirurgischen Anatomie des Menschen, 1879. In plate iii. he figures a mesial section of a male body in which the bladder was greatly distended. In the explanation of this plate he directs attention to the low position of the base of the bladder. The plate also shows very distinctly a marked shortening of the prostatic and membranous portions of the urethra. This subject is obviously worthy of more attention than it has yet received.

EXPLANATION OF PLATES.

FIGURE 1. Mesial section of pelvis of boy aged 5 years. empty and contracted.

Bladder nearly

FIGURE 2. Mesial section of pelvis of boy about 6 years old. Bladder dis

tended with two ounces of water.