By pouching of the bladder (Fig. 44) is understood that a depres sion is formed in the most dependent portion of the viscus in which the whole thickness of the wall is involved. It is for the most part met with in the senile adult bladder in connection with hypertrophy of the prostate and occasionally as a consequence of the pressure ex ercised by the presence of a stone. Mr. Buckston Browne" has illustrated how such a pouch may be the means of containing as well as conceal ing one or more stones. These pouches, when complicated with calculus and an enlarged prostate, not infrequently ren der the selection of lithotomy a necessity. A pouch that has once held a stone for some time is seldom fitted to hold anything else, and consequent ly an attempt should be made to dispose of it by some ade quate form of bladder drainage. In the general treatment of pouching and sacculation of the bladder, when not compli cated with stone, I must add my testimony to the great bene fit that has sometimes followed sea-voyages. I have known thick cystitic urine, due to the pollution of the general cavity of the blad der by the contents of a stagnant sac, entirely recover itself when placed under these conditions. The constant movement of the ship both by day and night, and in whatever position the body may oc cupy, renders stasis of any of the fluids of the body impossible, and thus one element necessary for decomposition is removed. The im
munity of seamen from stone and certain bladder affections may in some measure be due to this." In one instance at present under my observation where there is very little doubt the patient has a saccu lated bladder, the urine is invariably clear and normal when he is at sea, and turbid and offensive when he is on shore for any length of time. Yet in other respects, as far as I can judge, the conditions are the same.
The bladder wall is developed partly from hypoblast and partly from mesoblast; consequently, on the embryological theory of the origin of morbid growths, we may expect to find connective-tissue, vascular, and epithelial tumors. It is interesting to note, in associa tion with papilloma of the bladder, that the allantois, the hypoblast lining of which gives rise to the epithelial coating of the bladder, is also the source of the chorionic villi, the most perfect example of physiological papillary growths. The classification of bladder and prostate tumors adopted here is similar to that proposed by Mr. Paul," in a paper read before the British Medical Association in 1883. The former will be considered in the following order : (1) Myoma; (2) Fibroma; (3) Myxoma; (4) Sarcoma; (5) Papilloma; (6) Carcinoma.