Societies and Academies

Abstract

LONDON Royal Society, April 21.—H. W. McKenny Hughes: Induced melanism in Lepidoptera. Females of the Geometrid moth Selenia bilunaria, Esper, were collected in three different areas in southern and eastern England, as far as possible away from industrial areas. Two generations were fed upon pure untreated hawthorn, after which four subsequent generations were fed upon hawthorn treated with lead and manganese salts respectively. Brother and sister matings were adopted throughout the experiment. Adequate control broods were kept, and in all 3265 moths were reared. No melanic individuals appeared at any time, either in the control or treated broods.—S. Adler and O. Theodor: Investigations on Mediterranean kala azar (6). Canine visceral leishmaniasis. Eleven out of 100 dogs examined in Malta between June and November were found to be naturally infected with kala azar. Seborrhea and partial depilation are the most frequent signs of canine kala azar and were found in nine out of eleven cases. The skin condition is due to infiltration of macrophages round hair follicles. Infected macrophages are found throughout all parts of the skin, both in the areas of infiltration round the hair follicles and in normal dermis. Sandnies, P. perniciosus, were infected with Leishmania by feeding on the unbroken skin of three dogs. The infection rates were 62.5 per cent, 65.4 per cent, and 32 per cent respectively.—R. H. Stoughton: The morphology and cytology of Bacterium malvacearum, E.F.S. (2). Reproduction and cell-fusion. New morphological forms have been observed. The production of coccoid bodies, their liberation, and subsequent germination to form apparently normal rods, is described. The formation of densely-staining spherical bodies, apparently arising from the point of fusion of two cells, is described. These bodies are apparently liberated by the degeneration of the parent cell.