In order to decide between these three possibilities starvation tests were made on two dogs with complete isolation of the stomach from the central nervous system by section of the vagi and the splanchnic nerves and on one dog with the vagi nerves severed, the splanchnic nerve being left intact. The following is a brief summary of the results:
Dog VI.-Young Female. Section of the Vagi and Splanchnic Nerves Two Weeks before Starvation Period
4th day. 10:00 a.m. to 1:00 p.m., one group, type I contractions (15), fairly strong.
5th day. 2:00 to 5:00 p.m., type I contractions, fairly strong but with long intervening pauses. 6th day. 10:00 a.m to 12:00 m., 30 strong (type I) contractions ending in tetanus (Fig. 5/4). M
7th day. 1:00 to 4:30 p.m., continuous contractions of type III; tonus about 10 cm. bromoform.
End of experiment
Dog VII.-Adult Fairly Vigorous Female. Vagi and Splanchnic Nerves Cut
5th day. 9:00 to 11:00 a.m., 9 very vigorous contractions and tetanus periods.
6th day. 1:00 to 3:00 p.m., fairly strong contractions of type I; long pauses between contractions. 7th day. 1 :oo to 5:00 p.m., stomach hypotonic; no contractions. End of experiment
Dog VIII.-Young, Fairly Vigorous Female. Vagi Nerves Sectioned
3d day. 9:00 to 11:00 a.m., fairly strong type I contractions.
5th day. 1:00 to 5:00 p.m., strong (type I) contractions, long pauses between contractions.
6th day. 9:00 to 11 :oo a.m., stomach hypotonic, practically no contractions.
7th day. 1 :oo to 4:00 p.m., fairly strong type I contractions, prolonged and partly tetanic; long pauses between contractions. End of experiment
The gastric hunger contractions of Dog IV were absent on the seventh day of starvation, but Dogs V and VII showed either normal or greater than normal hunger contractions throughout the starvation period. Since the increase in the hunger contractions appeared to be just as marked in the dogs with the stomach isolated from the central nervous system as in normal dogs, it follows that the cause of this increase is not an augmentation of the vagus tonus.
These starvation periods were not of sufficient length to cause very marked asthenia either in the men or in the dogs (except Dog V). They do show that the hunger tonus and contractions persist with normal or greater than normal vigor during shorter starvation periods. Cases of gastric hypotonus and decreased gastric motility cannot therefore be due to starvation as such, but to some special and exceptional factors. The depression may be due (1) to a primary asthenia of the stomach; (2) to central inhibition via the splanchnic nerves (pains, depressions, etc.); (3) to acid inhibition from the stomach mucosa owing to eopious secretion of gastric juice. This question requires further investigation.