158 PHYSIOLOGY 



have become thick, and yet in a continual flow. But where there was 

 a continual flow, she wanted thin bile. Again, if she wanted thick bile 

 where it continued to flow, in those animals which have the gall- 

 bladder she needed not to have made a hepatic duct, but only a 

 hepato-cystic duct ; which would have poured it always into the gall- 

 bladder, which again would have poured out nearly the same quantity 

 by the cystic at all times ; but then it would have been thick bile. We 

 see something like this in fowls ; but then they have a hepatic duct 

 which constantly pours in thin. bile. 



Supposing that we wanted thin bile at all times, both that which is 

 wanted at certain times and that which is wanted constantly ; then it 

 would have only been the not making lymphatics to come from [and 

 absorb the watery part of the bile in] the gall-bladder. 



Now the thing to be considered is, why the constant bile should be 

 thin and the other [intermittent bile] thick ? 



It is disputed whether the gall-bladder secretes bile or not. This 

 perhaps can only be determined by diseases of this part. When Lord 

 Bristol was opened, there was found in the cystic duct a large gall- 

 stone which appeared to fill tightly the duct, so that no bile could pass. 

 The gall-bladder was very much contracted although not diseased, and 

 its contents were a pellucid slimy mucus, not in the least tinged nor 

 bitter to the taste. Vide Dissections, vol. p. ['? Wm. Clift.] 



As some animals have gall-bladders and others none, it may be asked, 

 What is the use of the gall-bladder ? Is it to keep bile for particular 

 times, or is it to keep a constant flow of bile ; supposing the liver to 

 secrete only at particular times ? However this be, the last does not 

 seem to be so probable as the first. 



Of the Pancreas. 



The pancreatic juice would seem to be absorbed. The cuttle-fish 

 would show this. [How? asks Wm. Clift 1 .] 



Of the Kidneys. 

 The bodies called kidneys are glands intended for a secretion of a 

 fluid, which in common language is called ' mine.' Their use is imme- 

 diately to carry out of the circulation such parts as are useless and 



1 [Hunt, Prep. No. 775: "Pancreas of the Cuttle-fish." It shows the numerous 

 follicles, communicating together so as to form small elongated groups or lobes, 

 whose common ducts open not directly into the intestine, but into the hepatic ducts, 

 extending along them from the lower part of the liver to the spiral laminated 

 duodenal cavity. Vide Physiological Catalogue, 4to, 1833, p. 229. Swammerdam 

 observes, of the spiral cascum of the Cuttle-fish, — " It contains a matter like the 

 pancreatic juice of other fishes.'' — Bibl. Naturse. fol. p. 889.] 



