Abstract
EDINBURGH. Royal Society, July 6.—G. Leslie Purser: Calamoichthys calabaricus Smith. Pt. i. The alimentary and respiratory systems. Calamoichthys is the less known of trie two genera of the Polypterini. The histology of the alimentary tract is not so complex as the anatomy would lead one to expect, as the intestinal epithelium is practically the same throughout its length; and as a whole the digestive tract is of a simple piscine type. Gills are well developed, but in addition there is, opening into the pharynx by a median ventral glottis, a pair of lungs, the minute structure and the vascular connexions of which show how well the pulmonary respiratory mechanism is developed.—W. W. Taylor: The precipitation of sols by polyvalent ions. With the alkali salts of methane-trisulphonic acid and naphthalenetrisulphonic acid, which are neutral, there is only one zone of precipitation of ferric hydroxide sol, which commences abruptly at about 0.0002 N and extends up to the saturated solution. It is not followed by a zone of no-precipitation. The range investigated was from 7 × 10-8 N to nearly 1.5 N. They thus fall in line with the neutral chloride and sulphate solutions. The two zones of precipitation, separated by a zone of no-precipitation (“reversal”) obtained with sodium phosphate, which contains OH' and no trivalent anion, is ascribed to the OH′. If this be the case, the analogous behaviour of negative sols with ferric and aluminium salts will be due to their hydrolysis. Whether the presence of a polyvalent ion is also necessary is not certain. With the neutral anions, more or less periodic variations in the rate of precipitation were observed; these are not due to errors in procedure. The valency rule does not hold in the case of the above trivalent anions.—E. Neaverson: Ammonites from the Upper Kimmeridge Clay. The Upper Kimmeridge Clay includes a variable series of clays and sands lying between the Gravesia zones of the Lower Kimmeridgian and the base of the Portland Stone Series. The zonal sequence is here tabulated with equivalent stratigraphical terms:
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Societies and Academies. Nature 116, 331–332 (1925). https://doi.org/10.1038/116331a0
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DOI: https://doi.org/10.1038/116331a0