ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 371 



tracted from the dead bacteria with, water, and are completely dissolved 

 by sulphuric acid, malt extract, and saliva, so that the resulting fluid 

 no longer reacts with iodine. Towards iodine these substances behave 

 after the manner of /3-amylose, amylodextrin, and glycogen. The rela- 

 tion of the red staining carbohydrate to glycogen and amylodextrin is 

 discussed, and it is held that, while the identity of the red staining 

 carbohydrate to glycogen has not been satisfactorily established from 

 a microchemical point of view, there is undoubtedly a close relation 

 between it, glycogen, and amylodextrin. Any definite opinion based on 

 microchemical methods is, of course, still less satisfactory. 



Influence of the Temperature of Liquid Air on Bacteria. * — Dr. 



A. Macfadyen records experiments which show that bacteria may be 

 cooled down to —190° C. for a period of 20 hours without losing any 

 of their vital properties. Numerous organisms were used, the extremes 

 of susceptibility being Spirillum cholerae asiaticse and the spores of 

 Bacillus anthracis. In nc instance was any impairment of the vitality 

 of the organisms detected ; even the photogenic bacteria, which when 

 cooled down became non-luminous, when thawed, reassumed their 

 luminosity with unimpaired vigour ; an excellent proof, moreover, of 

 the dependence of this luminosity on the vital activity of the cells. 



Thermophilous Bacteria, f — Herr G. Michaelis isolated four species 

 of thermophilous bacteria from different wells: — (1) B. thermophilus 

 aqualilis liquefaciens ; (2) B. therm ;ph. liq. aerobius ; (3) B. thermoph. 

 aquatilis chromogenes ; (4) B. thermoph. aquatilis anguinosus. These 

 bacteria are thin rodlets 2-4 /*. long ; they are motile, and form spores ; 

 they do not form indol. All four, except 1, attack grape-sugar, and, 

 except 2, are potential anaerobes. They are stainable by Gram's method 

 and are not pathogenic. Their optimum temperature lies between 50° 

 and 60°. At 57° they grow strongly and quickly; motility is well 

 marked ; spore-formation is copious ; pigment-formation and fermenta- 

 tion are good. At 70° involution forms are frequent. At 37°, except 

 in 3, growth is either ab.nt or scanty. 



Fruit-Ether-forming Bacteria.:}: — Herr A. Maassen describes four 

 new species of bacteria which, under certain conditions, produce an 

 agreeable odour resembling fruit-ether. Bacterium esterificans stra- 

 launense developes a faint aroma, and when cultivated in the ordinary 

 media quite loses after a time its ester-forming power. Bacillus esteri- 

 ficans is a spore-forming species which on certain media developes a 

 strong ethereal odour very much like that of fresh apples. In the 

 presence of pepton it forms sulphuretted hydrogen and mercaptan. 

 Glycerin and carbohydrates favour its growth, but not its ester produc- 

 tion. These bodies are not fermented, but are decomposed with the forma- 

 tion of acid. Bacillus esterificans fluorescens decomposes grape-sugar. 

 During the first few days the cultures exhale a faint ester aroma, but 

 later the odour becomes disagreeable and resembles that of trimethylamin. 

 Bacillus prsepollens is distinguished from other ester-forming bacteria 

 by numerous physiological characters. Its energetic peptonising action 



* Proc. Koy. Soc, lxvi. (1900) pp. 180-2. 



t Arch. f. Hygiene, xxxvi. (1899) p. 285. See Centralbl. Bakt. u. Par.. 2' 9 Abt., 

 Ti. (1900) p. 154. 



I Arb. a. d. Kaiserl. Gesund.-Amte Berlin, xv. O .)9) pp. 500-13 (3 pis.). 



2 C 2 



