280 Report on an Inquirij into the Nature, Causes, and 
may escape from the filament by a lateral opening. Or, lastly, 
the filaments may break up into a number of fragments, each 
containing one or two spores, as at 4, Fig. 2. 
Fig. 3. — Further Stages of Bacillus antliracis under Cultivation. 
7. Part of convoluted filaments in which spores have formed, and division is commencing in parts, 
from cultivation of Bacillus anthracis. 8. Similar process in another Bacillus not cormected with 
anthrax. 9. Portions of filament from 7 more highly magnified. 
The spores thus formed are capable of long dormancy, for 
months or years, and may then, given favourable conditions, 
grow again into rods and reproduce the disease. It is the 
formation of these spores, and their capacity for resisting 
changes of temperature and other adverse conditions, which 
makes the contagion of anthrax so persistent and so difficult 
to destroy. 
In some cases these spores, when kept under conditions which 
are only favourable to very slow germination, undergo a process 
of division by transverse fission, each spore first dividing across 
its length, and then each of these halves divide again transversely, 
so that each formed a group of four minute bodies, or sporules (as 
Ewart calls them); as seen at 6, Fig. 2, and still better at 
3, Fig. 5. 
The other course of change which may occur in the filaments 
is that seen at 1 and 2, Fig. 2, and at the bent filament in 
2, Fig. 1. The filament appears somewhat swollen : — in it (as 
in 1, Fig, 1) are seen a number of minute bright dots, which as 
a rule are towards the sides of the sheath, sometimes only here 
and there, but occasionally crowding the filament with bright 
oily-looking dots. In some cases the filaments break up into 
shorter pieces, as at 2, Fig. 2, whilst in this condition. It 
is probable that this may be regarded as merely a stage in 
spore formation, which here commences laterally instead of 
centrally. 
The more minute changes which take place in the course of 
growth and spore formation, will be better seen in Fig. 4, which 
is taken from cultivations of Bacillus antliracis, magnified 1500 
diameters. 
