ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 85 



purplish and later brownish. Bouillon is rendered turbid with the 

 formation of a surface ring and a coherent sediment. Indol is formed, 

 and nitrates reduced to nitrites. Milk remains unaltered. 



Defatted Tubercle Bacilli.* — J. Cantacuzene finds that dead and 

 defatted tubercle bacilli are toxic. Injection of a big dose rapidly 

 causes death with hypothermia, necrosis of the immigrant leucocytes, de- 

 generation of the renal epithelium, of the heart and muscle, and a marked 

 eosinophilia. In smaller doses, the effects produced are eosinophilia, 

 hypothermia, emaciation, formation of abscesses, and enormous enlarge- 

 ment of the spleen. The tuberculous new formations caseate and are 

 finally completely absorbed by the agency of giant-cells. The 

 inoculated animals react to tuberculin for several weeks. The defatted 

 bacteria when treated with Gram's iodine solution lose their toxicity, and 

 injection of such an emulsion imparts a considerable tolerance. The 

 absorption of the defatted bacteria and of the tuberculous deposit is 

 hastened by daily injections of potassium iodide, which stimulates the 

 phagocytic power of the mononuclear leucocytes. 



Bacteria and the Emission of Light.f — In a small brochure, 

 H. Molisch deals with the subject of emission of light by plants. The 

 production of light is confined to fungi, bacteria and Peridinee in the 

 plant world. The author determined that the luminosity of meat is 

 caused by a bacterium, and showed that the bacterium can generally be 

 produced in a few days by partially immersing a piece of meat in brine. 

 The emission of light from wood has been traced to the same source, 

 and similarly decaying leaves of oak and beech may become luminous. 

 The connection between nutrition, growth, and luminosity has been 

 studied by Beijerinck. As to the teleological factor in the production of 

 light, little is known except that it is an oxidation process. The author 

 postulates a substance, photogen, that produces light waves in the 

 presence of oxygen. 



Bacillus Enteritidis, Gaertner, and Bacillus pseudo-Tuberculosis, 

 Pfeifler4 — The chief differential characters, says E. Klein, between the 

 bacilli of the G-aertner group and the Bacillus pseudo-tuberculosis are 

 the following : The former are motile and multiflagellate ; B. pseudo- 

 tuberculosis is non-motile. The former produce gas in gelatin shake 

 cultures ; the latter do not. The former produce a uniform turbidity in 

 broth and in phenol broth ; the latter form granules and flocculi, the 

 broth remaining clear. In MacConkey's fluid the former produce acid 

 and gas ; the latter do not. Subcutaneous injections of B. pseudo- 

 tuberculosis give rise to chronic granulomatous inflammation ; while 

 injections of B. enteritidis cause acute septicsemic infection. 



Differential Criterion between Cholera Vibrio and certain other 

 Vibrios : the action of Formalin on their Gelatin Cultures.§ — 

 Mavrojannis shows that formalin in gelatin cultures fixes the gelatoses 



* Ann. Inst. Pasteur, xix. (1905) pp. 699-714. 



t Die Lichtenwickelung in den Pflanzen. See Nature, Nov. 23, 1905, p. 85. 

 % Trans. Patholog. Soc, lvi. (1905) pp. 132-5. 



§ Journ. de Phys. et de Path, gen., vi. (1904) pp. 273-7. See also Centralbl. 

 Bakt., lte Abt., xxxvii. (1905) p. 270. 



