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those specially engaged in plague work in India and elsewhere, opposes the view that the disease is of alimentary origin. The evidence upon which such opposi- tion is based is by no means obvious. My researches would appear to relegate to the alimentary canal, a most important part in the production of the disease and as a focus of entry of the B. pestis into the body, and the grounds upon which this conclusion is based are the following

(1.)

The symptoms complained of by plague patients during the earliest stages of the disease are referrable to the gastro-intestinal tract. Diarrhea and vomiting are frequently the first signs of the disease.

(2.) The gastro-intestinal manifestations are frequently-if not in most instances well marked previous to the appearance of anything like a peripheral bubo or secondary pneumonia.

(3.) The negative results obtained were after a most careful enquiry and

examination as to the question of skin inoculation of the virus. (4.) The presence of gastro-intestinal symptoms in plague infected individuals in whom a definite focus of skin incorporation of the plague virus was present.

(5.) The condition found in the gastro-intestinal tract and neighbour-

hood on post-mortem examination is strongly suggestive of alimentary incorporation of the B. pestis. For details, wide the

Results of Post-mortem Examination.

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(6.) The B. pestis is present in hoards in the faces of man and animals.

suffering from plague.

(7.) The B. pestis may be demonstrated in large numbers in the mucous

membrane and other couts of the gastro-intestinal gut.

(8.) The B. pestis may reach the small intestine by way of the mouth

without much chance of injury. The bacillus is capable of resist ing the action of dilute acids for an appreciable length of time. The amount of acid, namely, hydrochloric acid, present at any time in a normal stomach, is about 0.02% The B. pestis would appear to be able to withstand the action of such a quantity of acid. WILM states that plague bacilli live for 2 days in % of hydrochloric acid. The German Plague Commission found that pure cultures of plague bacilli were killed by the action of 1 in 1,000 solution of hydrochloric acid only after half an hour. GIANA and GOSIO state that 1 in 100 hydrochloric acid kills the B. pestis in one hour and à 0-5 % solution of the acid only after six hours.

The B. pestis is evidently little affected by the gastric juice. (9.) The pathological changes found in the mesentery are suggestive of

alimentary contraction of the disease. The general enlargement and oedema of and hæmorrhagic extravasation into and around the mesenteric lymphatic glands with the presence of enormous numbers of plagne bacilli in such foci speak for such a mode of introduction of the virus.

(10.) Experimental evidence in animals yields constant positive results. Pigs, fowls, sheep, monkeys, etc., if fed on plague infected material contract the disease with certainty.

(11.) Infection per os in plague is the most certain means of production.

of the disease in animals.

(12.) The post-mortem appearances found in artificially infected animals- are strongly in favour of an alimentary mode of infection. (13.) The B. pestis is found in great numbers in the forces of animals

suffering from plague.

(14.) The rat is infected per os. This is the usual mode of infection

in this animal.

(15.) Food and articles of diet have been found infected with the B

pestis. (Vide Food in relation to the Spread of Plague.")

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