IN SUSCEPTIBLE ANIMALS. 459 



a figure 8, and are only stained at the point of contact of the two segments. 

 In potato cultures they are sometimes elongated and swollen at one ex- 

 tremity. 



Stains with the usual aniline colors and by Gram's method. 



Biological Characters. An aerobic and facultative anaerobic, non-lique- 

 fying, actively motile bacillus. Spore formation not observed. Grows in the 

 usual culture media at the room temperature more rapidly at 37 C. In 

 gelatin stick cultures yellowish- white colonies are developed along the line 

 of puncture ; at the bottom these may have a diameter of one to two millime- 

 tres, and they have a brown color. Upon the surface an irregular, lobulated, 

 whitish, translucent, paraffin-like layer is developed. At the end of eight 

 days the surface growth consists of large, confluent, transparent plaques, 

 with irregular outlines and crenated, elevated margins ; along the line of 

 puncture large, separate, lenticular or spherical colonies are seen ; these 

 have a brownish-white color. At the end of two months the surface growth 

 is concentric and still more transparent, while the colonies near the surface 

 have become almost brown. Upon the surface of agar, at 37 C., a narrow 

 band is developed along the line of inoculation ; above, this is composed of 

 transparent, shining, flat, round colonies having a diameter of one milli- 

 metre or more ; below, the colonies are confluent and form a transparent, 

 whitish layer. In glycerin-agar development is still more abundant, and 

 may already be perceived at the end of twelve hours. Crystals are seen 

 below the surface in agar cultures and about the superficial colonies in gela- 

 tin. Upon potato a uniform, thin, grayish, verv transparent layer is de- 

 veloped, which sometimes has a brownish-gray tint. At the end of a few 

 days the potato acquires a brownish color. In bouillon cloudiness of the 

 medium is apparent at the end of ten hours ; twenty-four hours later a 

 whitish precipitate is seen at the bottom of the tube, which is more abun- 

 dant when the culture medium contains glucose; later a thin pellicle is 

 seen upon the surface and the bouillon acquires a yellowish color. 



Pathogenesis. Recent cultures are pathogenic for rabbits, guinea-pigs, 

 pigeons, and mice, which die from general infection in from two to four 

 days. Old cultures are less virulent. 



87. BACILLUS OF LUCET. 



Obtained by Lucet (1891) from chickens and turkeys suffering from an 

 infectious form of septicaemia characterized by dysenteric discharges " Dy- 

 senterie epizootique des poules et des dindes." 



Resembles Bacillus gallinarum of Klein, and is perhaps identical with 

 this microorganism. 



Morphology. Short bacilli, from 1.2 to 1.8 /* long, usually in pairs. 



Stains with the usual aniline colors, but not by Gram's method. 



Biological Characters. An aerobic and facultative anaerobic, non-lique- 

 fying, non-motilebaicillus. Spore formation not observed. Grows slowly in 

 the usual culture media at the room temperature more rapidly at 37 C. 



In gelatin plates small, shining, moist, white, circular colonies are devel- 

 oped, which look like little drops of wax ; later these increase in size, and 

 especially in thickness, forming hemispherical masses. In gelatin stick cul- 

 tures grayish, punctiform colonies are developed along the line of puncture, 

 and upon the surface a circular, prominent, whitish plaque. Streak cultures 

 upon the surface of gelatin are in the form of a dirty-white or grayish- white, 

 moist streak, with regular margins, limited to the line of inoculation, but 

 increasing in thickness until it breaks loose and slips down the oblique sur- 

 face of the culture medium. The deposit which collects in this way acquires, 

 as it becomes old, in the deepest portion a reddish color. Upon agar it forms 

 a thick, yellowish- white, mucus-like layer with straight or slightly dentate 

 margins. In bouillon it produces a decided clouding of the liquid, and an 

 abundant grayish, pulverulent sediment accumulates at the bottom of the 

 tube ; the bouillon after a time becomes transparent above this sediment and 



