Chap. 20.] The Bladder. 223 



navel by ligaments, which are the remains of two 

 arteries of the foetus, and as its fundus pro] eels into 

 the cavity of the abdomen, the bladder is alfo con- 

 nected to the peritoneum, which covers part of its 

 fundus. 



The coats of the bladder are, firft, a coat of cel- 

 lular fubftance, by which it is connected to the neigh- 

 bouring parts ; sdly, a mufcular coat, the fibres of 

 which, beginning from the neck, afcend on both 

 lides, towards the fundus. At the neck the fibres 

 crofs each other, and in this manner form a fphinfter, 

 by which animals are enabled to retain the urine; 

 and yet a continuation of the fame fibres towards the 

 fundus aflifts in expelling it. In this part, as well as in 

 the tongue and mouth, we have an inftance of the dif- 

 ferent parts of the fame mufcular fibres counteracting 

 each other. 



" The third coat of the bladder is like the nervous 

 coat of the interlines, and bears the fame name. The 

 inner coat has many foldings, and is plentifully fup- 

 plied with mucus. The fundus of the bladder alfo 

 derives a coat from the peritoneum. The ufcs of the 

 bladder are to receive the urine, to. retain it for a time, 

 and to expel it through the urethra from the body. 



Had the peritoneum been fpread over the bladder 

 in its whole extent, the weight of the vifcera in our 

 erect pofture would have fo borne upon it, that a con- 

 fiderable quantity of water could not have been col- 

 lected there. ' The peritoneum, however, by puffing 

 from the fides of the abdomen over the fuperior part 

 of the bladder, forms a lupport for the incumbent vif- 

 cera, and preferves a certain fpace below, where they 

 cannot prefs. In the quadruped, where, from the ho- 

 rizontal pofition of the body, the abdominal vifcera do 



not 



