Abstract
LONDON. Royal Society, February 29.—Sir Archibald Geikie, K.C.B., president, in the chair.—Dr. A. Harden and Dorothy Norris. The bacterial production of acetyl-methylcarbinol and 2: 3-butylene glycol.—II. Péré considered that glyceraldehyde was produced during the bacterial fermentation of sugars, and advanced the hypothesis that all sugars undergoing such decomposition were primarily broken down to glycerose. The authors have repeated his experiments, and find that the volatile, reducing, and lævorotatory substance which he considered to be glyceraldehyde is in reality acetylmethylcarbinol. Hence the above hypothesis cannot be considered as proved. A quantitative examination has been made of the products formed by the action of B. lactis aërogenes (Escherich) on glycerol under anaërobic conditions. These consist of ethyl alcohol and formic acid, comprising 60 per cent, of the whole, together with smaller quantities of acetic, lactic and succinic acids and 2:3-butylcne glycol, carbon dioxide, and hydrogen.—H. S. Ryland and B. T. Lang: An instrument for measuring the distance between the centres of rotation of the two eyes. The apparent position of a pin fixed at a known distance in front of a scale is taken with each eye singly. The operation is repeated with the pin at a different distance, the other conditions remaining unaltered. From the data thus obtained the distance between the centres of rotation of the two eyes can be calculated. The result is independent of variations in the distance between the pupils, and the process can be applied in cases of squint. In an alternative method three pins in a row parallel to the scale are used.—J. F. Gemmill: The locomotor function of the lantern in Echinus, with remarks on other allied lantern activities. (1) Locomotion out of water (reference is made to previous accounts by Romanes and Ewart).—The urchin raises itself from time to time on the tips of its teeth in preparation for a forward “step” or lurch. The “step” is then brought about (a) by strong pushing or poling on the part of the lantern, (b) by similar but weaker action on the part of the spines, (c) by the influence of gravity acting at a certain stage. Active progression by lantern alone is possible in small and medium-sized urchins. Progression by spines alone is very limited indeed. An urchin can travel with the help of its lantern even when loaded to the extent of half a pound or more. There is usually some rotation as well as progression, but the two are not associated as cause and effect. The causes of rotation are discussed, and an analysis is given of the lines or curves of progression in relation to rotation. Other points to which attention is directed are:—muscles involved; strength of effort; change of direction; inversion; equatorial section; recording surfaces of plasticene and other substances; the inertia and momentum of the rhythmic action. (2) Locomotion under water.—Here the lantern is not needed for ordinary locomotion, particularly over more or less horizontal surfaces. There are, however, various circumstances, normal and experimental, in which it is employed with effect-for example, when the urchins are loaded or travelling up a slope on certain surfaces, or only partially immersed, or mounting rapidly up a vertical surface. (3) The locomotor action of the lantern is a particular manifestation of a rhythmic functional activity which can also subserve feeding (no doubt the most important function), boring, and “forced respiration.”—Captain A. D. Praser and Dr. H. L. Duke: The relation of wild animals to trypanosomiasis. (1) Trypanosonia uniforme was the only species of trypanosome obtained as the result of examination of wild animals, including thirty-two Lake-shore antelopes. (2) The available evidence points to bush-pig, crocodile, monitor, frog, and fowls being refractory to T. gambiense. (3) The edible rat, which is susceptible to T. gambiense, can, by virtue of its habits, be of little importance in considering the question of a reservoir.—Dr. H. L. Duke: The trasmission of Trypanosoma nanum (Laveran). This trypanosome can be transmitted by Glossina palpalis, the proportion of positive flies obtained being relatively large, and indicating that this fly may play an important part in the spread of the disease in Uganda.—E. H. Ross: The development of a leucocytozoon of guinea-pigs. The paper describes an investigation of some remarkable structures found in the mononuclear leucocytes (lymphocytes) of the blood of guinea-pigs; they are known as “Kurloff's bodies.” There has been considerable controversy regarding the nature of these bodies, some authorities describing them as vacuoles containing secretion products, some as symbiotic structures, as chlamydozoa, as cytoryctes, as parasites, and as spurious parasites. By a new technique for in vitro staining, known as the jelly method, the minute structure of these bodies can be seen, while the lymphocytes which contain them are stained alive. The method shows conclusively that Kurloff's bodies are living parasites. The method also shows how the bodies develop within the lymphocyte host, for the chromatin within them stains in the various phases, and the whole development can be followed from the earliest Leishmania-like inclusion in the leucocytes until ultimately the leucocytozoon is seen to contain a mass of spirochaste-like bodies which have been likened to gametes. The blood of such guinea-pigs shows, when examined with the dark-ground illumination, free-swimming spirochastes, and these have been fixed and stained. The details of the jelly method are described.
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Societies and Academies . Nature 89, 51–53 (1912). https://doi.org/10.1038/089051a0
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DOI: https://doi.org/10.1038/089051a0