CHAP. IV.] BILIARY FISTULA. 269 



> s. 



will, in its entirety, flow externally, so long as the external exit 

 is free. If the cannula which ,has been fitted into the fistula is 

 closed, either by a stopper or by an accidental plug of mucus, the bile 

 will flow into the intestine. Such biliary fistulas are termed by 

 Schiff, who has employed them frequently in his researches, amphi- 

 bolic fistulas 1 . Such fistulas offer so many advantages that it 

 appears strange that they have not been more commonly preferred 

 to the fistulse with occlusion of the common bile-duct. The chief 

 of these advantages is firstly, that the operative procedure required 

 for their establishment is comparatively simple and that, conse- 

 quently, the chances of recovery are much greater than when the 

 bile-duct is divided. Secondly, that animals with amphibolic fistulas 

 do not suffer in general health to the same extent as those from 

 whose alimentary canal the bile is continuously cut off: and thirdly, 

 that the secretion of bile may at any time be studied under condi- 

 tions which much more nearly approach the normal than can be the 

 case if the bile is permanently withdrawn from the intestine. 



Temporary Temporary biliary fistulas have often been estab- 



biiiaryfistuiae. lished in the dog and cat. The abdomen having been 

 opened and the common bile-duct exposed, a glass tube is introduced 

 into it, the cystic duct being sometimes ligatured. To the glass tube 

 is attached an indiarubber tube, by which the whole of the bile 

 excreted is conveyed externally. 



The establishment of temporary biliary fistulas has often been 

 practised in the case of the guinea-pig. The large size of the gall- 

 bladder in this animal and the readiness with which it can be drawn 

 to the surface obviating the principal difficulty encountered when 

 operating on dogs. When, however, the common bile-duct of the 

 guinea-pig is tied the animal dies in the course of about twenty-four 

 hours 2 . 



SECT. 2. THE SECRETION OF BILE, THE CIRCUMSTANCES UNDER 

 WHICH IT OCCURS, AND THE CONDITIONS WHICH INFLUENCE IT 3 . 



1. Absolute amount of Bile secreted. 



The secretion of bile is continuous, though the rate at which it 

 proceeds varies very greatly. 



1 From d/z0i/3oXia, the state of being attacked on both sides. For references to 

 Schiff' s papers and a discussion of his investigations refer to p. 278 et seq. 



2 The reader who desires additional information on the subject of biliary fistulse is 

 referred to the already quoted paper by Schwann, as well as to Kuhne's Lehrbuch, 

 p. 69: Heidenhain, 'Anlegung von Gallenfisteln ' in Hermann's Handbuch, Vol. v. i. 

 pp. 24 ( J 251 : Colin, Physiologic comparee, Vol. i. p. 851. 



3 In the preparation of this section the Author has availed himself of much 

 information contained in the admirable article by Professor Heidenhain, entitled 

 ' Allgemeine Verhaltnisse der Gallensecretion ' in Hermann's Handbuch, Vol. v. r. p. 

 251 et seq. 



