224 SUMMARY OV CURRENT RESEARCHES RELATING TO 



treating with ammonia and staining with silver colloid, the author 

 appears to have established the areas surrounding the bacilli as true 

 capsules. 



Micrococcus Esterificans.* — Beck describes this organism as resem- 

 bling Staphylococcus pyogenes aureus, and producing a characteristic fruity 

 aroma. The aromatic substance is insoluble in alcohol, but dissolves in 

 ether, chloroform, and sulphide of carbon. Butter treated with broth 

 cultures of the coccus, keeps fresh for about five days longer than 

 ordinary butter made from the same cream. It is suggested that this 

 organism might be useful in the manufacture of butter, by improving 

 its taste and keeping property. 



Bacillus Aterrinus Tschitensis.f — W. N. Klimenko has isolated 

 from the air of his clinical laboratory, at Tschita, a bacillus that pro- 

 duces a brown pigment ; it is an actively motile rod with rounded ends, 

 resembling B. mesentericus vulgaris ; it occurs most often singly, rarely 

 in pairs, and sometimes forms threads ; it has a single centrally-placed 

 oval spore ; it stains by ordinary analin dyes and by Gram's method, 

 but is not acid-fast : it is a potential aerobe : the optimum tempera- 

 ture is 36°-40° 0. 



On agar the colonies appear after 16 to 20 hours, and by reflected 

 light both superficial and deep colonies have a white colour with a 

 lustreless wrinkled surface ; but after 48 hours the deep colonies by 

 transmitted light, and the superficial colonies by reflected light, have a 

 dark brown colour ; after the fourth day a production of brown pig- 

 ment commences to diffuse into the medium around the superficial 

 colonies. Pigment is also formed by colonies grown on gelatin, and the 

 medium commences to liquefy after the third day, and on the surface 

 of the liquefied gelatin there floats a pellicle which develops a brown- 

 black pigment ; growth on agar containing sugar or glycerin shows no 

 formation of gas ; pepton-broth is clouded, a pellicle being formed 

 which develops a brown-black pigment ; on potato the growth is at 

 first dry and wrinkled, but later is thick and greasy, having the colour 

 of cafe-au-lait, the colour of the potato itself being unaltered ; milk is 

 clotted, the coagulum being subsequently dissolved. The organism is 

 not pathogenic. It closely resembles B. mesentericus niger and B. lactis 

 Gorini. 



Purple Bacteria. J— H. Molisch has classified these organisms into two 

 groups, viz. those that deposit sulphur granules in their bodies and those 

 that do not. Each of these is again subdivided into two sub-groups or 

 families, according as the cells are free or are associated, and these 

 families comprise separate sub-families, depending on the form of the 

 cell division, the property of swarming, and on the morphology of the 

 cells. The author finds that the susceptibility of those bacteria to light 

 extends to all the visible and invisible ultra red rays. On examining 

 the giving off of oxygen under the influence of light, it was found that 

 carbonic acid was not assimilated, so that the colouring matter of these 

 organisms is not analogous to chlorophyll. 



* Centralbl. Bakt., 2te Abt., xix. (1907) p. 594. 



f Op. cit., 2te Abt., xx. (1907) p. 1. J Op. cit., 2te Abt., xx. (1908) p. 289. 



