206 
Ward . — Thames Bacteria , III. 
Cultures in gelatine-drops gave positive results, and helped 
materially in further distinguishing this form. In a gelatine- 
drop made at 10.30 a.m., temp. = 2i°, a short rod 3 x 0*75 [i was 
fixed at 1 1. 15, and had (Fig. 16 b) divided at 11.50 into two 
rodlets each 1*5 x 0-75 /x : by 1 p.m. each had grown to 2 x 
0*75 ft, and by 2.40 one was distinctly constricted and the 
other faintly so — each 4 x 0-75 ft, and by 3.30 each had again 
divided and four short rodlets now lay side by side. (See 
Fig. 16/) 
By 6.15 p.m. there were about sixteen rods crowded into an 
oval colony measuring iox6/q temp. = 20-5°; and by 10.30 
next morning the colony was perfectly spherical, and 44 1 u in 
diameter: the temperature had fallen to 18 0 during the night 
and was now 1 9 0 C. At 3 p.m. the colony was of the same 
shape, and with no sign of liquefaction or movement, and 
measured 52 m across; temp. = 31°. At 9 p.m. the diameter 
was 56 temp. = 1 9 0 , and no further progress was observed, the 
gelatine-drop having dried up somewhat. 
In another case, in a broth-drop made at 10.30 a.m., the 
rodlets measured 3 x 1 ju, or somewhat thinner, and moved 
with the characteristic waggling movement. Rapid division 
occurred, and in a few hours most of the rods measured 
4 x 1 y, and some had grown to filaments of 10-12 up to 
30-40 ft, and with serpentine movements. On the second 
day most of the rodlets measured 1-5 to 2 x 1 y, and on 
the third day most of them were so short as to be nearly 
cocci. 
Plate-cultures at 18-20° C. showed colonies under the in 
twenty-four hours, the submerged ones being smooth in out- 
line but irregularly oval or circular, yellowish, granular ; and 
the emerged colonies coming out as thin, hyaline, faintly 
granular more or less circular films. 
In forty-eight hours the colonies are visible to the eye as 
pale white circles with a central spot, and exhibit a curious 
crystalline appearance and bluish sheen when held up. Under 
the |rd each emerged colony is found to have a dense liquefy- 
ing core of dark granules, whence radiate coils and tresses, 
