SMALL STOMACH A MIRROR OF THE LARGE ONE. 107 



It must occur to every one who becomes acquainted for the first time 

 with our investigations upon the secretion of gastric juice, that while 

 the main stomach during digestion is filled in the ordinary way, 

 the miniature stomach remains constantly empty of food. One might 

 suppose that the contact of food in the one case, and its absence in the 

 other, would involve an enormous difference in the working conditions 

 of the two stomachs. After a careful investigation into the facts of 

 the case, we may state with all positiveness that this apparently 

 weighty consideration is, after all, of no moment. When juice flows 

 at the beginning of the meal from the gastric cul-de-sac, its activity at 

 the time must be accepted as identical with that of the large stomach. 

 Such an assertion is incontrovertible when all the data of this and the 

 two preceding lectures are taken into consideration-. The secretion 

 begins with the psychic excitation of the secretory nerve centres, and 

 this excitation naturally spreads in identical fashion to all points of the 

 mucous membrane and its glands, whether in the large or small cavity. 

 But with this proved, we must (to preserve uniformity in our conception) 

 admit a probability, that the nervous system acts in a similar way 

 during the remaining phases of the secretory process. 



The condition of matters has here radically changed when con- 

 trasted with former times, where notwithstanding the endeavours of 

 several investigators, success was not attained in attempts to dis- 

 cover a nervous mechanism for the gastric glands. But such a 

 mechanism has now been discovered, and indeed a complex one, to 

 which a work must be assigned. If, then, the beginning of the secre- 

 tory process is identical in the two stomachs ; what is the condition, after 

 the secretion has set in, which we assume has its causation in a local 

 excitatory effect produced by the food ; in other words, what occurs 

 when the psychic influence has come to an end ? At all events, 

 we still see a flow from the small stomach after the psychic secretion 

 has run its course, or even when it has not at any time been 

 present ; such, for instance, as happens when the food is placed un- 

 observed into the stomach of the dog. These facts we shall take as the 

 basis of our argument. How are they to be explained ? How can 

 local events in the large stomach produce an effect, on the small ? 



The functional connection between the two stomachs can only be 

 effected by one or other or both of two systems of the body the 

 circulatory or the nervous. One may, for instance, conceive that 

 the chemical materials which excite the secretion are absorbed from the 

 digestive canal, and carried by the blood either to the secretory centres 

 which they excite or even to the glands themselves. This supposition 

 is capable of being easily tested. If it be correct, we ought to obtain 

 the same effect when the substances in question are introduced into the 



