TRAKSACTIONS OF SECTION D. 747 



(G) Sarcina liqiififaciens. — Under ahigli power it mucli resemLles Sarcina lutea. 

 It liquefies the gelatine, however, much more rapidly, whilst on ap^ar-agar its 

 growth is Tery rapid, producing an almost colourless (very faintly greeu) expansion. 

 In broth the liquid is clear, free from pellicle, with a deposit which later becomes 

 of an orange colour. The colonies appear very faintly' green, and form slowly a 

 surface-depression. Under the microscope they are highly irregular in contour, with 

 a denticulated and lobular edge. 



(7) Micrococcus ffi(/as.—Thia is seen to be a large micrococcus, .sometimes as 

 much as 1'7 /x in diameter : they are frequently adherent in pairs. It liquefies the 

 gelatine slowly, rendering it turbid. On agar-agar it forms a cream-yellow expan- 

 sion. In broth it produces a whitish deposit, the liquid being clear and free from 

 pelhcle. The colonies appear as pin-heads of a faint cream colour, which cause a 

 depression iu the gelatine. Under the microscope they are seen to be circular in 

 sliape, with a slightly irregular edge and a cloudy centre. 



(8) Micrococcus chryseus. — This is a micrococcus varying in size, going up to 

 1 /x in diameter. The largest cells exhibit a division. It liquefies the gelatine 

 slowly, the depression being filled with semi-liquid cream-coloured matter. On 

 agar-agar it forms a shining expansion of a light orange colour. In broth it pro- 

 duces a dirty white deposit, the liquid remaining clear and free from pellicle. The 

 colonies appear as pin-heads of a yellowish colour. Under the microscope they are 

 seen to be generally round, the more developed colonies showing a finely granular 

 edge. 



(1) Bacillus aurescens. — This is seen imder a high power to be a short bacillus 

 occurring singly, in pairs, and in threads of three and four. The individual bacilli 

 are fi-om three to five times as long as broad, with rounded ends. In drop-cultiva- 

 tions they exhibit vigorous vibratory and rotatory motion, but no movement of 

 translation was observed. "When grown on gelatine it forms a light orange-coloured, 

 dry, and much crumpled expansion. It does not liquefy the gelatine. On agar- 

 agar it forms also a dry, light-orange surface-growth. In broth the liquid is clear ; 

 there is a deposit of cream-yellow matter, and the surface is covered with a delicate 

 cream-yellow pellicle. The colonies appear as pin-heads of a faint orange colour. 

 Under the microscope they are seen to be not perfectly circular, and have a very 

 slightly j agged edge. 



(2) Bacillus aureus. — With a high power this is seen to be a bacillus forming 

 line graceful threads, which are considerably longer than those formed by Bacillus 

 aurescens. In drop-cultivations they exhibit only vibratory motion. On gelatine 

 it. forms a dry crimipled expansion, which is of a much deeper orange colour than 

 B. aurescens. In old cultivations slight liquefaction of the gelatine takes place. 

 On agar-agar it forms an orange growth, which is less crumpled and less dry in 

 appearance, but deeper in colour than that of B. aurescens. In broth it resembles 

 B. aurescens, but the deposit and pellicle are deeper in colour. The colonies differ 

 little from B. aurescens, except that they are deeper in colour and more rapid in 

 their growth. 



(3) Bacillus citreus. — This is seen under a high power to be a short fat 

 bacillus, about one-and-a-half to twice as long as broad. Sometimes they hang 

 together in chains of three and four. The average length of a pair is about 3-ifi ; 

 the ends are roimded and sometimes pointed, especially in those cases where 

 division has taken place. Often it assumes forms of peculiar shape, some of the 

 bacilli being bent and often club-shaped. It is non-motile. On gelatine it grows 

 .slowly, producing shining and smooth lemon-yellow expansion. On agar-agar it 

 forms a moist, shining, sulphur-yellow expansion. When grown in broth the liquid 

 remains clear, free from pellicle, and forms a slight yellowish deposit at the bottom. 

 The colonies appear as dots of a strong yellow colour. Under the microscope they 

 are more or less circular in .shape, with an almost smooth edge. 



(4) Bacillus plicatus. — Under a high power this is seen to be a very minute 

 bacillus about l| times as long as broad. It forms short threads, and is very 

 motile. No spore-formation was observed. It forms a much crumpled and folded 

 greyish expansion, the surface of which is abundantly pitted and excavated. No 

 liquefaction of the gelatine takes place. On agar-agar it grows very similarly, only 



