G. S. Graham-Smith 
130 minutes a chain of four bacilli had been produced (Fig. 4), and 
after 170 minutes a chain of eleven bacilli (Fig. 5). By this time the 
chain had developed a decided bend at B, and a less marked one at A. 
Owing to the fact that the adjacent bacilli slipped slightly out of the 
line of the chain at these points their positions could be easily recognised 
during subsequent growth. It is of interest to note that the linear 
distance separating,, the points remained approximately the same, as 
long as the points continued to be recognisable (Figs. 5 to 10). The 
next four figures (6, 7, 8 and 9) illustrate the formation of a primary (IV) 
and two secondary (I and II) loops. Fig. 10 shows further develop¬ 
ment of these loops and the addition of another (III), and also illustrates 
how the pressure of the developing loops causes the formation of parallel 
chains of bacilli. The development of further loops and increased 
parallelism is shown in Figs. 11 and 12, and in the latter figure the 
commencement of a secondary series of loops in the right free portion 
of the chain is seen at Y. In Fig. 1.3 a complete young colony is 
illustrated. It consists of a single chain of closely approximated 
bacilli, extending freely as a slightly wavy thread over the surface of 
the medium at both ends. The centre of the chain is much twisted 
and has formed numerous loops, and bands of parallel bacilli. On the 
free portion of the chain extending to the right a secondary system of 
loops (Y) has developed. The chain is incompletely broken at four 
points (A, C, D and E). These incomplete breaks are no doubt due 
to partial ruptures of the capsule, for it seldom happens that the chain 
becomes completely divided at such places. The appearances seen at 
one of these points is illustrated on a larger scale at B, B 1 . 
In Plate III a series of photographs (x 240) are reproduced illus¬ 
trating the formation of a superficial colony from two anthrax bacilli 
lying close together. 
In Fig. 1 a long bacillus is shown with an abrupt angle near its 
centre. To the left of the angle and above the first bacillus lies the 
much shorter second bacillus. Fig. 2 (35 minutes) shows an increase 
in the length of both bacilli, and accentuation of the angle to such a 
degree that the portions of the bacillus forming it are almost parallel. 
Fig. 3 (120 minutes) shows a great increase in the length of the 
chain. That portion which originally formed the angle has grown out 
into a long curved process, composed of two parallel threads. The 
1 In order to avoid confusion the segmentation is omitted in the later figures, 11 to 13. 
The continuation of the left free portion of the chain is illustrated in the detached figure 
below the colony. 
