748 REPOKT— 1887. 



the expansion is rather more moist. In broth it renders the liquid very slightly 

 turbid, causing a dirty white deposit, and forms on the surface a tough, irregular 

 pellicle. The larger colonies, which are on the surface, exhibit an indentation in 

 the centre ; as growth proceeds the centre remains depressed, whilst the edge 

 becomes irregularly folded and raised, until at length the colony is only attached 

 to the gelatine by a comparatively narrow portion of the growth. The substance 

 of the colony is very tough in character. Under the microscope the small colonies 

 have a rough, irregular edge, and vary in shape and degree of roundness. The 

 larger colonies are very irregular in shape. 



(5) Bacillus chlorinus. — This is seen to be a very short bacillus, varying from 

 •5/x to 1'5/i in length, and about half as broad as long; the ends are rounded. 

 It occurs singly and in short chains. Only vibratory motion was observed. It 

 liquefies gelatine slowly, producing a lemon-yellow deposit. On agar-agar it pro- 

 duces a strong, almost uniform, shining surface-growth of a greenish-yellow colour. 

 In broth it renders the liquid slightly turbid, and produces a dirty-yellow deposit ; 

 no pellicle is formed. The colonies form shining greenish expansions. Under the 

 microscope they are seen to have a thin, smooth edge, with very fine granular contents. 



(6) Bacillus polymorphus. — This organism exhibits a great variety of forms, 

 even in cultivations only one day old. Small fat bacilli, almost like micrococci, are 

 found; then there are longer forms, frequently occurring in pairs and also forming 

 strings of irregular thickness. These strings show frequently no signs of division, 

 and sometimes reach Vl fx in length. The isolated bacilli are •8/i in length 

 and nearly as wide. All these various forms were obtained from one and the same 

 colony. Vibratory motion only was observed. On gelatine it grows slowly, pro- 

 ducing an expansion regular in its shape and minutely serrated at the edge. The 

 surface of the growth is white, but as the cultivation gets older the centre becomes 

 tinted slightly yellow. No liquefaction takes place. On agar-agar it grows also 

 with a highly serrated edge. In broth it forms a white deposit and produces a thin 

 cloudy-white pellicle on the surface. The colonies are circular and bluish-white, 

 with a small yellow spot in the centre. On the surface they form pin-heads. 

 Under the microscope the surface colonies are seen to be circular, with an iiTegu- 

 larly corrugated edge. The central portion is cloudy and surrounded by a distinct 

 ring. The smaller colonies in the depth are very irregular in shape and resemble 

 the corolla of a flower. 



(7) Bacillus 2»'ofusus. — This is seen to be a short fat bacillus with rounded ends. 

 The length reaches about 1-7 /x and the width about -5 n, but its dimensions 

 are very variable. They only exhibit vibratory motion. On gelatine it spreads 

 over the surface in a thin layer, which has a beautiful opalescent appearance when 

 viewed by transmitted light. On agar-agar it forms a much thicker growth, form- 

 ing a smooth whitish lobular expansion. In broth it forms a whitish deposit, 

 whilst on the surface it produces thin granular floating matter. The colonies form 

 an opalescent e.xpansion on tlie surface, with a very irregular contour. Under the 

 microscope the surface colonies exhibit a dense centre surrounded by a very thin 

 granular expansion having a highly irregular contour. Against the light these 

 surface colonies are of a beautiful azure-blue colour. 



(8) Bacillus pestifer. — This is seen to be a large thick bacillus about 3-4 /z in 

 length and from '8 ju to 1'7jli in thickness. It forms threads sometimes of 

 great length, which give rise to winding vermiform figures. Their movement is 

 slow and undulating, the single bacilli exhibiting most motility. No spore-formation 

 was observed. In gelatine it produces an almost colourless feathery expansion, 

 which causes slow liquefaction of the medium. On agar-agar it forms a moist and 

 shining grey-white expansion, which sometimes becomes very much wrinkled. In 

 broth the liquid is turbid, free from pellicle. A small quantity of white deposit is 

 formed. The colonies appear as white specks only to the naked eye, but under the 

 microscope they are seen to be very irregular in contour, consisting of threads 

 branching into the surrounding gelatine ; later the centre becomes very dark and 

 cloudy, but the edge remains light. Later these feathery contours can be seen with 

 an ordinary magnifying glass. In all cultivations this organism gives rise to a most 

 disagreeable odour, somewhat resembling that of putrid blood. 



