Klebs and Lubarsch found ulcerations of Peyer's patches which, for a moment, gave rise to a suspicion of typhoid. Flesch found ulceration of the jejunum and swelling of the mesenteric glands. Kuskow has made the most detailed study of these conditions, especially the "hyperemic" inflammation and the resulting necrosis of the mucous membrane, more particularly of Peyer's patches and the solitary follicles. These conditions were most frequently found in the duodenum; then in the stomach, ileum, and jejunum. Mosler describes a case of " gastro enteritis hemorrhagica " of considerable clinical interest. Weich selbaum described cases of hemorrhagic enteritis of the small intestine and of croupous enteritis. In two such cases he found the Diplococcus pneumonias in the intestine.

We may briefly describe a case of Weichselbaum's: A girl, twenty one years of age. Influenza. Epileptiform convulsions; vomiting; diarrhea; herpes nasalis. Slight distention of the stomach, and especially of the right iliac region. Death on the eleventh day. Postmortem examination: Bronchopneumonic areas. Acute enteritis of the ileum. Bloody contents in the small intestine. Mucous membrane swollen, partly much injected, and partly the seat of hemorrhagic infiltration.

The grave form of influenza enteritis may, in consequence of the circulatory disturbances in the intestinal walls, give rise to paresis of the gut with meteorism and persistent constipation, and even to obstruction (see below). The intense abdominal pain, the frequent vomiting, and the collapse may simulate the features of general peritonitis.

If the influenza enteritis attacks only the lowest portion of the ileum and the cecum, with marked pain in the region of the appendix, the picture of appendicitis may be produced. "Nous l'avons vu simuler une perityphlite classique" (Teissier).

The cases termed." typhlitis and perityphlitis following influenza," which occur in the reports from all countries, are to be thus explained, except that they were not usually, as assumed, cases of appendicitis, but of a true typhlitis.

In the pandemic of 1889 I observed some cases of simultaneous influenza with typhlitis which I did not venture to bring into direct causal relation with the influenza; I believed that I had to deal with a coincident occurrence of influenza with an ordinary appendicitis. But the subsequent accumulation of reports in the literature, together with my own pathologic experiences (see below), have since convinced me of the existence of an influenza typhlitis.

We have frequently laid stress on the fact that the rarest complications of influenza occasionally occur in local groups: this applies also to typhlitis. Teuscher (Saanen) saw, within three to four weeks, 12 influenza patients with typhlitis.

The severe form of influenza enteritis may lead to peritonitis, generally with a fibrinous, rarely with a purulent, effusion. The following observations of our own may serve as instances:

1. A boy, aged twelve, was suddenly taken ill with convulsions, high fever, and all the signs of the respiratory form of influenza. At the end of the second day violent abdominal pains; retraction of the abdomen; extreme sensitiveness to touching the abdomen, particularly in the region of the cecum; vomiting; constipation; collapse. In the following days meteorism with diarrhea set in. Death on the sixth day. Postmortem examination: The peritoneal surface of the lowest portion of the small intestine and the cecum was of a dirty red color. Fibrinous deposits on the inflamed coils of intestine. No fluid exudate in the peritoneal cavity. The mucous membrane of the lower portion of the small intestine, of the cecum, and of the ascending colon was of a dark red color, and in the condition of the above described hemorrhagic enteritis. Appendix intact.

2. Typical beginning of influenza (in the pandemic of 1889) in a woman forty five years of age, with rigor and high fever. On the third day, symptoms of peritonitis; meteorism; vomiting. At first two bloody diarrheic stools, then total constipation.

On the eighth day, with continuance of the fever, total obstruction with fecal vomiting. In the left iliac region a large intestinal coil projects and is easily defined. A surgeon called in consultation recognizes von Wahl's sign, and in spite of the high fever pronounces it to be a volvulus of the sigmoid flexure. The operation is fixed for the next morning. The patient died during the night. Postmortem examination: The intestines are normal as regards position. Peritoneum of a dark reel color; slight fibrinous peritonitis. The mucous membrane of the lower portion of the ileum is of a dark red color and swollen. The mucous membrane of the ascending colon and the sigmoid flexure, which latter seems much distended and thickened, is of a dark red color, and in the condition of the above described "hemorrhagic diphtheric enteritis."

Peritonitis as a sequel of influenza is repeatedly mentioned in the official German collective investigations. Such cases have also been described by Kundrat, Kelsch and Antony, Wallis, Buchheim, Siro tinin, Isnardi, Cnyrim, and in the Swiss reports. Kuskow describes a case of local peritonitis in the splenic region which originated from a " parenchymatous necrosis" of the spleen. " Influenza peritonitis," so far as at present known, exists only as a sequel of the severe form of influenza enteritis described above. There is no convincing instance recorded to show that the influenza bacilli can pass directly into the peritoneum from the blood or from the intestine with mucous membrane intact, and there cause peritonitis, even granting, however, that such a case as that described in the German army report deserves consideration. The presence of the influenza bacillus in the intestine in hemorrhagic enteritis or in the peritoneum in peritonitis has not yet been established.

The gastro intestinal influenza may give rise to a severe vomiting.

Bose* (Cologne) observed in an influenza pneumonia a "gastroenteritis acutissima" which had the appearance of a severe attack of cholera, but it terminated favorably.