722 ADDITIONAL SPECIES OF 



starch many of the bacilli, at the end of two or three days, contain granules 

 which acquire a deep-blue color when treated with iodine solution. Upon 

 agar plates (with 1.5 per cent of grape sugar), in an atmosphere of hydro- 

 gen, colonies are developed in fifteen to eighteen hours, which under the 

 microscope are seen to be round or elliptical in form and to consist of closely 

 interwoven filaments ; as a rule, the margins are not well defined, and radiat- 

 ing filaments are given off from the felt-like colony. In deep stick cultures 

 in agar, growth commences at a depth of one and one-half centimetres below 

 the surface; later, when the oxygen is displaced by the gases produced, it 

 approaches the surface. The growth along the line of puncture has an ir- 

 regular outline with wave-like projections. In gelatin (with 1.5 per cent of 

 grape sugar) growth begins, in deep stick cultures, about two centimetres 

 below the surface ; much gas is developed and the gelatin is quickly lique- 

 fied. In bouillon (with 1.5 per cent of grape sugar) an abundant develop- 

 ment occurs within twenty-four hours in an atmosphere of hydrogen. The 

 fluid becomes clouded and much gas is developed; at the end of three days 

 the fermentation ceases, the bouillon becomes clear, and a thick, white de- 

 posit is seen at the bottom of the tube. In milk, contained in flasks com- 

 pletely full, and from which the oxygen has been expelled by boiling, 

 growth commences near the bottom, where at the end of fifteen hours a 

 transparent layer of serum is seen, from which numerous gas bubbles are 

 given off ; the fermentation progresses rapidly, and at the end of eighteen 

 hours the coagulated casein and particles of fat have accumulated at the 

 upper part of the flask; the pressure of gas is so great that many of the 

 flasks are blown into fragments; at the end of a week development has 

 ceased and the casein is almost entirely dissolved, the contents of the flask 

 consisting of a transparent, yellowish fluid, with spongy masses of fatty 

 material upon the surface and a flocculeiit, white deposit at the bottom. 

 Upon potato, in an atmosphere of hydrogen, development occurs in the in- 

 terior of the potato, but not upon the surface. 



Not pathogenic. 



Note. Botkin is not able to identify the bacillus described by him with 

 butyric-acid bacilli described by Pasteur, Cohn, Hueppe, and other authors, 

 which for the most part have been cultivated only in liquid media. He re- 

 marks that it is differentiated from Clostridium butyricum of Prazmowski 

 (Vibrion butyrique of Pasteur) by the fact that it does not decompose cellu- 

 lose or salts of lactic acid. It closely resembles a butyric-acid ferment de- 

 scribed by Perdrix, but is differentiated from it by the fact that the bacillus 

 of Perdrix does not liquefy gelatin. 



463. UROBACILLUS PASTEURI (Miquel). 



Obtained by Miquel from decomposed urine. 



Morphology. Bacilli differing greatly in dimensions in different media 

 the diameter may be as much as 1.2 ju. In urine to which two per cent of 

 urea has been added it is usually seen in the form of short rods united in 

 chains of two to six elements. In gelatin cultures containing urea the ba- 

 cilli are from 4 to 6 M long and are usually in pairs. 



Biological Characters. An aerobic, liquefying, motile bacillus. Forms 

 spherical spores, usually solitary, and situated at one extremity of the rod. 

 Grows at the room temperature in the usual culture media when these are 

 made alkaline by the addition of ammonia, or when urea is added. In gela- 

 tin plates containing urea minute colonies are developed within twenty- four 

 hours and an ammoniacal odor is given off ; under a low power the colonies 

 are seen to be spherical or oval, yellowish, and surrounded by dumbbell- 

 shaped crystals ; at the end of eight days the gelatin commences to liquefy, 

 and after a time has the consistence of castor oil. In ordinary flesh-peptone- 

 gelatin no development occurs, unless the medium has a distinctly alkaline 

 reaction. No growth occurs in the usual agar-agar medium, but when urea 



