Gr. S. GrRAHAM-SMITH 
31 
Such loops are produced by a modification of the folding arrangement, 
which is well exemplified in Figs. 4, 5 and 6. As the result of the 
approximation of the bacilli forming the marked angle at the lower 
portion of the chain (Fig. 4) a lateral process composed of two parallel 
bacilli is produced in Fig. 5. In the course of further growth one of 
the organisms forming this process grows faster than the other and the 
chain formed from it develops a secondary angle. The result is an 
irregular loop. Figs. 7 and 8 (xloO; 195 and 243 minutes) show 
the results of further growth. In the latter it is seen that the parallel 
chains of bacilli, well shown in Fig. 6, tend to develop considerable 
curves. In Fig. 7 a chain of bacilli from another colony has grown 
up and touched a prolongation of the colony under consideration at 
the left hand lower corner of the photograph. 
In spite of the fact that the bacilli appear to have become separated 
at some of the angles, especially when these have become very acute, no 
separation really occurs in the early stages of growth. If such a chain 
as that shown in Fig. 5 is disturbed by a current of water its shape 
becomes completely altered, but it floats away without losing its 
continuity. In the later stages of growth complete ruptures are 
occasionally seen. 
Fig. 10 (x about 30) shows the margin of a fully developed colony 
with a thin expansion composed of numerous angular loops. 
Deep colonies show a modification of the process just described. 
The formation of one is illustrated in Diagram 3. 
In Fig. 1 a chain with two angles and several curves is shown. 
Five minutes later (Fig. 2) both the curves and the angles have become 
better marked. During subsequent growth numerous angles are 
developed, each of which becomes more acute and ultimately results in 
a process, composed of two parallel bacilli, united at their distal ends, 
growing out in a direction more or less at right angles to the direction 
of the original chain. Most of the curves also sooner or later develop 
into angles. The lateral processes at a later period produce secondary 
lateral processes of their own in the same way. Although the parallel 
bacilli forming the lateral outgrowths are at first united at their distal 
ends, there is a tendency for the uniting portion of the capsule to rupture 
after the outgrowth has reached a considerable size, probably due to un¬ 
equal growth in the chains formed from the two original bacilli producing 
the outgrowth. This is clearly seen in the outgrowth produced from 
the well marked angle in the centre of the chain in Fig. 1, and also 
in that produced from the large curve near the bottom of this figure. 
