ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 201 



hanging drop into an enclosed drop, and (b) by altering the surface of 

 the spore by means of corrosives. 



Hanging drop preparations of particles, of approximately equal size, 

 of carbon, mastic, sulphur, barium sulphate, Staphylococcus aureus, etc., 

 were not affected by the air- water interface, and remained in free 

 Brownian movement to the bottom of the drop. Two factors may be 

 regarded as entering into the phenomenon of the immobility of bac- 

 terial spores at fluid interfaces : (1) a diminution of surface energy 

 due to some peculiarity of the spores, causing them, as soon as they 

 are brought within the range of action of the surface forces, to be 

 drawn into close approximation to the interface ; and (2) the abnormal 

 viscosity of surface layers of liquids, which destroys the Brownian 

 movement of the spores. Particles other than spores, not producing a 

 lowering of surface energy, are not drawn into such close contact with 

 the interface, and so do not experience the surface viscosity. There is 

 at present no evidence of an electrical factor in the phenomenon, but 

 further work on this point is in progress. 



Identification and Classification of Cellulose-dissolving Bacteria.* 

 K. F. Kellerman, I. 6. McBeth, F. M. Scales, and N. R. Smith have 

 carried out investigations upon these organisms, and find that they 

 have a wide distribution. Fifty soils from different parts of the United 

 States were examined, and in each case two or three types of cellulose- 

 dissolving organisms were found. In this paper there is given a 

 detailed account of the morphological, cultural, and bio-chemical proper- 

 ties of twenty-one different types. At the end of the paper the chief 

 characteristics of these bacteria are tabulated. The most satisfactory 

 method of isolating these organisms was found to be the following : a 

 portion of the sample of soil or other material was added to a filter- 

 paper nutrient solution, and after a few transfers in this medium was 

 plated successively on cellulose-agar, starch-agar, and finally beef -agar. 

 Many of these types grow better on peptone-media than on media con- 

 taining inorganic nitrogen, in the form of ammonium sulphate. Most 

 of them grow better and show greater activity under aerobic than under 

 anaerobic conditions. Kept under laboratory conditions for any length 

 of time they undergo marked physiological change, and may lose their 

 power of destroying cellulose. 



Bacilluria in Typhoid Fever. f — A. Patrick reports upon the 

 results of bacteriological investigation of the urine in twenty-four cases 

 of typhoid fever. In six cases no typhoid bacilli were found, but 

 organisms of the typhoid-coli group not hitherto described. In none of 

 the seventeen cases in men was the B. coli recovered, although nearly 

 all the women showed it. The atypical organisms reacted in varying 

 manner with sugar-fermentation tests, but had certain features in 

 common. They were all Gram-negative, all formed acid in glucose, and 

 acid and gas in maltose, mannite, saccharose, galactose, levulose, rham- 



* Centralbl. Bakt., 2te Abt., xxxix. (1914) pp. 502-22. 

 t Journ. Path, and Bact., xviii. (1914) pp. 365-78. 



