This subject has been dealt with by so many investigators and, within recent years in the United States, in such minute detail that it would seem surprising that no definite conclusion has yet been reached as to the cause of the disease or the actual part played by the diet in bringing about the condition.

Professor L. S. Dudgeon, when consulting bacteriologist to the Forces in the Balkans during the late war, had tried the effect of drying the stools of suspected dysentery patients on some porous material so as to leave only the mucus. In bacillary cases he found that a more abundant growth of dysentery bacilli was obtained from the dried mucus than from the untreated specimen, so that the drying had no harmful effect on the organisms. He used for this purpose unglazed red tiles such as were to be found locally, and suggested that the method should be given a more thorough trial with a more satisfactory type of tile made in this country. With this view the following experiments were made.

In nearly every case where canned meat or fish is condemned as unfit for human consumption, the action is based upon the physical features of the unopened tin, which are held to indicate decomposition of the contents. No studies of canned foods would therefore be complete without some detailed consideration as to the real harmfulness of such rejected foodstuffs.

(1) Our experiments support the view that influenza is casued by B. influenzae, and that pneumococci and certain streptococci are the most important agents of secondary infections. No new type of bacterium was discovered, and no evidence was obtained of the presence of an ultra-micrascopic virus.

(2) B. influenzae appears more toxic for rabbits and mice when grown on fresh liver or kidney media than when grown on blood agar or in blood broth, and this is especially so when the kidney or liver is obtained from an animal of t he same species that has previously been inoculated with a culture of the influenza bacillus.

(3) Three fairly distinct special forms have been isolated from cultures of B. dysenteriae. They are probably not sexual units or stages in a true life cycle. Special large forms have also been obtained from cultures of B. influenzae, but these reverted back to the normal small type after several sub-cultures.

(4) A filter-passing material has been found associated with certain micro- cocci from vaccinia and in pure cultures of members of the dysentery-typhoid- coli group of bacteria. This material breaks down and dissolves the bacteria of the cultures, and the “infection” can be carried to fresh normal cultures. The evidence is against its being a living ultra-microscopic virus infecting the bacteria, but it may have some connection with the special forms. No definite evidence of a similar dissolving material has been found associated with cultures of the influenza bacillus.

(5) There is some indication that one or more of the forms isolated from pure cultures of dysentery bacilli may be special toxin-producing units, also that this function is at its maximum when the bacilli are first produced by the normal small forms or by sexual units of a normal culture. This may possibly be the case also with special forms that have been found in cultures of the influenza bacillus.

(6) It is believed that non-pathogenic wild varieties of ultra-microscopic viruses must exist in nature, and that they should present less difficulty in cultivation than the pathogenic varieties. Cultivations were made from filtrates of soil, faeces and water on various special media, and the tubes incubated in various gases. The chief gases tested either alone or mixed were oxygen, nitrogen, carbon dioxide and sulphuretted hydrogen. All the results were negative, but some interesting deposit colonies were obtained on media con taining a small quantity of sodium sulphide.

(7) The influenza bacillus grows in symbiosis with amoebae on blood agar, and in such cultures the bacillus lives considerably longer.

(8) The influenza bacillus grows in symbiosis with a small spirillum that was isolated from a grass emulsion, and in symbiosis with an extremely minute and delicate bacterium isolated from garden soil; after passing the emulsions through a Berkefeld filter. With these delicate bacteria the influenza bacillus will grow on media containing no blood, and if an egg medium is used the mixed growth is dense, heaped up and brownish in colour. In such cultures the in fluenza bacillus may live for months.

(9) The influenza and other bacilli will grow in an atmosphere of pure oxygen or pure carbon dioxide under diminished pressure.