CONTENTS. xvii 



PAGE 



181. Peptone and albumose. Parapeptone. Classification of proteids . 325 



182. Circumstances affecting gastric digestion ; acidity, temperature . 327 



183. The nature of the action of gastric juice. Pepsin .... 328 



184. The action of gastric juice on gelatin, chondrin, &c 329 



185. The action of gastric juice on milk. Curdling of milk. Casein. 



Rennin , 329 



SECTION II. 



THE ACT OF SECRETION OP SALIVA AND GASTRIC JUICE AND THE NERVOUS 

 MECHANISMS WHICH REGULATE IT. 



186. The evidences of the existence of a nervous mechanism . . . 332 



187. The nerves of the submaxillary gland 333 



188. The reflex secretion of saliva by means of the chorda tympani 



nerve 333 



189. The nature of the action of the chorda tympani nerve. Influence 



of atropin 335 



190. The effects on the submaxillary gland of stimulating the cervical 



sympathetic nerve 337 



191. The nervous mechanism of the parotid gland 338 



192. The general features of the secretion of gastric juice . . .338 

 193. The nervous supply of the stomach. The action of the nerves 



obscure 339 



194. The influence of the absorption of food in promoting secretion . 339 



The Changes in a Gland constituting the Act of Secretion. 



195. The appearances presented by the pancreas during secretion ; the 



histological changes 340 



196. The changes in an albuminous gland during secretion . . . 342 



197. The changes in a mucous gland during secretion .... 344 



198. The changes in the central cells of the stomach during secretion . 346 



199. The general nature of secretion. Loading and discharge . . 347 

 200. The formation of the ferment ; zymogen, trypsin, and trypsinogen, 



pepsin and pepsinogen 348 



201. The nature of the act of secretion itself. The flow of fluid. ' Secre- 

 tory ' and ' trophic ' fibres 350 



202. The functions of the epithelium of the ducts 361 



203. The formation of the free acid of gastric juice 352 



204. Why the stomach does not digest itself 352 



SECTION III. 



THE PROPERTIES AND CHARACTERS OP BILE, PANCREATIC JUICE, AND 

 Succus ENTERICUS. 



Bile. 



205. The characters of bile 354 



206. The pigments of bile. Bilirubin 356 



