ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 101 



tension acting on the cholesterol fatty acid mixture. This mixture is 

 quite different from the correspondim: ester, the acid presumably existing 

 as an "acid of crystallisation." Anisotropic globules and myelin forms 

 occurring in the tissues are, therefore, no evidence of the presence of 

 oleates or cholesteryl esters as suggested by Adaini, Aschoff. and others. 

 Anisotropic globules and anisotropic myelin forms are probably identical 

 in structure, though differing in shape ; it is possible that their presence 

 in some tumours has given rise to the suggestion that " parasites " were 

 responsible for the condition. Finally, the association of cholesterol and 

 fatty acid in unstable combination being so frequent, it may be deduced 

 that cholesterol lias an important place in the processes of fat metabolism. 



Crystals in Tumours.* — C. Powell White, as the result of various 

 micro-chemical experiments, comes to the following conclusions : (1) 

 That crystals consisting of a loose combination of cholesterin with fatty 

 acids, lecithin, or other substances occur in or among the cells of 

 malignant tumours, and in some other conditions. (2) These crystals 

 seem to be associated with cell proliferation rather than with cell 

 degeneration, in which condition simpler crystals of fat, fatty acids, or 

 cholesterin are more usual. (3) There are grounds for supposing that 

 cholesterin may be in some way associated with the regulation of cell 

 proliferation. 



Crystals in Fat-cells.f — T. Lorrain Smith and C. Powell White 

 conclude that the crystals found in fat-cells, hitherto spoken of as 

 margarine, margaric acid, stearic acid, etc., are in reality those of 

 neutral fats. 



Quekett Microscopical Club.— The 451st Ordinary Meeting was 

 held on November 6, 1908, the President, Professor E. A. Minchin, 

 M.A., F.Z.S., in the chair. Reference was made to the death, on 

 October 11, of Mr. W. Saville Kent. F.L.S., F.Z.S., etc., author of the 

 well known manual of Infusoria, The President exhibited and described 

 a number of preparations of blood-parasites— trypanosomes and trypano- 

 plasms— of fresh-water fish, chiefly from the Norfolk Broads. It was 

 supposed that the infection of the fish was effected by leeches. The 

 group was entirely confined to the Vertebrates ; nearly every known 

 species was the host of a trypanosome, but very many are quite harmless. 

 Mr. T. A. O'Donohoe read a note on " The Photographic Evolution of 

 the Fine Structure of the Podura Scale." He had photographed the 

 fine mycelioid structure and minute horizontal filaments joining the 

 vertical lines described by Mr. Nelson (see this Journal, 1907, p. 400). 

 Mr. F. P. Smith contributed a paper on "Some British Spiders taken 

 in 1908." He also gave a lecture, illustrated with lantern slides, on 

 " Flies, from several points of view." The " points of view " dealt with 

 were those of the man at the museum, the individual who recognises 

 some 40,000 species of flies, then the man with the Microscope and the 

 man with the pocket-lens. Following these were the man at the [arm, 

 the medical man, and the man in the street, and the final view-point— 

 a consideration of those creatures which assisted in the destruction ot 

 superabundant flies. 



* Journ. Pathol, and Bact., xiii. pp. 3-10. t Med. Chron., 1907. 



