1. Pigeons fed on daily rations of polished rice equal to 1/20th their initial body-weight develop symptoms of polyneuritis in about three weeks and usually lose considerably in weight.2. The efficacies of various ox-tissues for preventing polyneuritis have been determined, and the tissues arranged according to their anti-neuritic powers are in the following descending order: liver, cardiac-muscle, cerebrum, cerebellum, voluntary muscle, and (cows') milk.3. Alcoholic extracts of the excreta of a hen fed on unpolished grain and of the faeces of a rabbit fed on bread and cabbage cured polyneuritis in pigeons. The whole content of anti-neuritic substances present in the dietary was therefore not absorbed or else some amount is synthesised by the bacteria of which the faeces consisted to a considerable extent. No conclusions can consequently be drawn as to the actual distribution of the active substances in the animal body, until the extent to which the various tissues are absorbed from the alimentary canal of birds has been determined.4. Nuts (husked filberts) are very efficient in preventing polyneuritis, being even superior to lentils and husked barley. Cheddar cheese, on the other hand, even in considerable amount, has no preventive effect.5. Malt extract taken from two different samples readily cured polyneuritis in pigeons. A third sample however even in large doses had no curative action.6. For the prevention of beri-beri egg-yolk, heart-muscle, liver, nuts, barley, and lentils can be recommended as suitable foodstuffs with which to supplement the polished rice diet. As meat (voluntary muscle) has been frequently found to be ineffective in preventing epidemics of beri-beri, its replacement by heart and liver in mixed diets would be a considerable improvement, because, not only are these tissues when suitably prepared as nutritious as voluntary muscle, but they also contain the anti-neuritic substances in much higher concentration.

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IT is only comparatively recently that precise knowledge has been obtained in regard to the important problem of polysaccharide synthesis by bacteria. This advance has been due to the work of Hibbert and co-workers , who succeeded in isolating in the pure state and also on a large scale the polysaccharides formed by the activity of the micro-organisms B. mesentericUs, B. subtilis, and Acetobacter xylinum, and ascertaining their chemical structure.The polysaccharides synthesised by the closely related organisms, B. mesentericus and B. subtilis from sucrose and raffinose [1930; 1931, 1, 3; 1932] were found to be identical in chemical nature and to be "fructosans" of the laevan type. These laevans, consisting entirely of fructofuranose units are formed synthetically by the activity of a bacterial enzyme through the condensation of molecules of fructofuranose liberated in the nascent state in the initial hydrolysis of the sucrose and raffinose. The foregoing organisms were thus only able to produce a polysaccharide from carbohydrates, e.g. sucrose and raffinose, containing fructofuranose units; and such sugars as maltose, lactose, glucose, fructose (fructopyranose) were found to be unsuitable starting materials for synthesis. Ac. xylinum (the sorbose bacillus) synthesised cellulose [1931, 2, 4; 1934] from various carbohydrates and polyhydric alcohols, and it was discovered that the forms of cellulose produced by bacterial synthesis from glucose, fructose, galactose, sucrose, mannitol and glycerol were chemically identical, and also identical with cotton cellulose.The experimental work described in the present paper deals mainly with the problem of enzyme formation and polysaccharide synthesis by (1) bacteria related to B. mesentericus and (2) bacteria pathogenic to plants. Apart from the work of Ruhland [1906], no systematic researches appear to have been carried out, so far, in connection with polysaccharide formation in the latter group of micro-organisms.Ruhland studied the synthetic activities of B. spongiosWus, an organism causing disease in cherry trees in Germany, and stated that a pentosan of an araban type was formed by the growth of this organism in sucrose and raffinose agar media. On account, therefore, of the possible interest of the subject in plant pathology, and also because of the chemical interest of the phenomenon of pentosan formation by a micro-organism, an investigation on polysaccharide synthesis by plant pathogens has been carried out. Furthermore, very little information is available concerning the role of synthesising enzymes, the nutritional conditions essential for their formation in bacteria and also their activity. An investigation of the biochemical conditions influencing the develop- ( 2267 )

The rate of external work done against the resistance of a respiratory circuit was measured from pressure‐volume diagrams. Eight subjects breathed through the circuit at many levels of exertion. At any given minute volume the rates of external respiratory work were similar for all subjects. The circuit was also ventilated by a sine‐wave pump at corresponding minute volumes. The rate of work done by the pump at all minute volumes corresponding to exercising men was also similar. It was, therefore, concluded that in estimations of the rate of respiratory work on exercise, it is justifiable to assume that the human respiratory wave behaves as a sine wave.