ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 571 



with the above salts. In the case of monkeys, the culture was ad- 

 ministered by the mouth after the purgative effect due to an ingestion 

 of sodium sulphate had been produced, and then either six or twelve 

 hours later 40 c.cm. of a 2 p.c. solution of thorium ordanthanum sulphate 

 was given by the mouth. In the case of the six hours' intervals, the 

 monkeys survived after treatment with either of the salts, but with the 

 twelve hours, the animals died when lanthanum sulphate was adminis- 

 tered, but survived when thorium sulphate was used. 



Nitrogen Fixation by Azotobacter in Substrata Poor and Rich 

 in Nitrogen.* — J. Hanzawa states that mixed cultures of different 

 strains of Azotobacter were found to be more efficient than the same 

 bacteria in pure cultures, especially in aqueous solutions of mannitol. 

 The nitrogen of humus and small amounts of nitrates were almost with- 

 out effect on the fixation of nitrogen by pure cultures of Azotobacter. 

 In presence of nitrogen amounting to 2*5 p.c. of the amount of carbon, 

 nitrogen fixation is retarded, and with large proportions of nitrogen, 

 inhibited. Under natural conditions it seems probable that soil nitrogen 

 can only seldom, if at all, have an unfavourable action on nitrogen 

 fixation. Some humus substances seem capable of being utilized as 

 source of energy in the fixation of nitrogen. The humus of farmyard 

 manure gave positive results, whilst that of green manure gave negative 

 results. 



Metabiotic Action of Ultra-violet Rays. Theory of the Pro- 

 duction of New Microbic Forms by the Action on the Different 

 Nutritive Functions. f — Victor Henri and Mine. Victor Henri made a 

 comparative study of the development of normal anthrax bacillus and 

 two new forms ; (1) cocciform-^, taking Gram's reagent ; (2) slender 

 filaments, not taking Gram's reagent, yellow in colour, which they call 

 anthrax-y. f The culture media consisted of mineral salts, together with 



(a) one of the carbohydrates, dextrose, sucrose, maltose, lactose, or starch ; 



(b) one of the nitrogenous substances, ammonium lactate, ammonium 

 citrate, glycin, a-alanin, asparagin, or Chapoteaut's pepton ; (c) hydro- 

 chloric acid or sodium hydroxide at a concentration of N/200. 



Normal anthrax does not develop on media containing ammonium 

 salts or amino-acids as the nitrogenous nutrient, but only in media 

 containing pepton. The form S } behaves exactly like normal anthrax. 

 Anthrax-y develops in the presence of both ammonium salts and amino- 

 acids. None of the three forms develops in an acid medium, but all 

 prefer an alkaline to a neutral medium. Normal anthrax develops better 

 on a medium devoid of carbohydrates than in the same medium with 

 carbohydrates present, and if grown under the latter conditions a whole 

 series of modified forms is obtained. For the form S x there is no ap- 

 preciable difference. Anthrax-y develops best in the presence of carbo- 

 hydrates, and often it will not grow in a medium containing pepton 



* Centralbl. Bakt., 2teAbt., xli. (1914) pp. 573-6. See Journ. Chem. Soc, 

 cv. and cvi. (1914) pt. 1, p. 1113. 



t Comptes Rendus, clix. (1914) pp. 413-15. See Journ. Chem. Soc, cv. and cvi. 

 (1914) pt. 1, pp. 1112-13 X See this Journal, ante p. 292. 



