ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 613 



classes of moulds and not to one mould in particular, since the products 

 of the destruction and decomposition of the wood are not always the 

 same, and seem to be brought about by different enzymes. The author 

 refers to the observations of Tubeuf on the mould of "dry rot" — 

 Mentlius lacrymans — which appears to grow best in a medium contain- 

 ing carbon in the form of pure cellulose, but grows badly with carbon 

 in the form of pine shavings. 



Coniophora cerebella is one of the most widely distributed wood- 

 destroying moulds. The author obtained a fresh mycelium from a 

 telegraph post ; a fruit-bearing portion was placed on bread pap, and 

 after a few days at 15° C, a mycelium grew, from which, by subculturing, 

 a pure culture was obtained. It grows well on alkaline media ; it can 

 obtain its nitrogen from ammonia, but has no denitrifying action on 

 nitrates ; on pine or beechwood saw-dust moistened with water, it grows 

 badly, but if moistened with a nutrient mineral salt solution good growth 

 occurs at 15°-17° C. The author finds that the destruction of the wood 

 is greater than that required as nourishment of the mould, since if wood 

 totally destroyed by Coniophora cerebella is powdered and moistened with 

 nutrient mineral salt solution, it forms a good medium for the growth 

 of this mould. After the destruction of wood by a mould has proceeded 

 to a certain degree, the destructive process ceases. The author thinks 

 that this is analogous to the alcoholic fermentation of yeast, the 

 products of the metabolism having a hindering effect on the growth of 

 the mould. All the derivatives of dextrose, mannose, and galactose serve 

 as good sources of carbon, but lamilose and arabinose are unsuitable. 



Cultivation of Bacillus fusiformis.* — X. Lewkowicz finds that 

 this organism, which is a normal inhabitant of the mouth, and a 

 probable factor in the production of inflammation of the jaw, ulcerative 

 stomatitis, etc., is best grown on glucose agar to which serum has been 

 added, the colonies appearing after 24 hours, in the deep oxygen-free 

 layers of the medium, about 12 to 15 mm. from the surface. The 

 bacillus has a great tendency to polymorphism, and only quite young ' 

 cultures show the regular round-ended rods in any proportion ; spindle 

 and thread forms are very common, the bacilli being often joined in 

 pairs. Quite young cultures stain regularly, but never by Grain's 

 method. The bacillus is non-motile, and does not form spores. Cultures 

 have a characteristic nauseous odour. The microbe is pathogenic for 

 laboratory animals. Introduction into the mouths of healthy children 

 gave negative results. 



Voges and Proskauer's Reaction for Certain Bacteria.f — A. 

 Harden, from chemical examinations of the products formed by Bacillus 

 lactis aerogenes and other bacteria from glucose medium, finds that 

 Yoges and Proskauer's reaction is due to acetylmethylcarbinol. This 

 substance in the presence of potash and air is oxidised to diacetyl which 

 reacts with some constituent of the pepton-water in the medium and 

 gives the characteristic fluorescent colour. 



* Centralbl. Bakt., l*e Abt. Orig., xli. (1906) p. 153. 

 f Proc. Roy. Soc, Series B, lxxvii. (1906) p. 424. 



