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 of 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 351, 



§ 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 of Bile, Pancreatic Juice, and 



Succus Entericus. 



Bile. 



§ 205. The characters of bile 354 



§ 206. The pigments of bile. Bilirubin 356 



