CHAP, X.~--MORPHOLOGY OF THE BACTERIA.-—ENDOSPOROUS BACTERIA. 467 
acute angles, and are at the same time often collected together in great numbers into 
bundles or sheaves and coiled round one another; such formations appear as flaky 
precipitates in larger quantities of fluid. The mode of spore-formation in the filaments 
is the same as in the preceding species. The ripe spores are as broad as the mother- 
cells but much shorter, and roundish to ellipsoidal in outline; they are usually set at 
liberty soon after reaching maturity by the disorganisation of the membrane of the 
mother-cell. They behave in germination like the spores of the preceding species, ' 
with the difference only that they have not been observed to part with an empty 
membrane; I have at most seen a form of cap on the extremities of the spore, 
Fig. 194 z, and sometimes it seemed as if a small delicate cap was at length removed 
from them. 
In some cultures, as for example in solutions of peptone, I have seen the filaments 
of this Bacillus break up over a wide area into round cells, cocci, which collect together 
into groups forming lumps or clusters. These with some doubtful exceptions were 
found to be dead. When removed into a good fresh nutrient solution they showed no 
signs of growth but gradually perished, while a few initials gave rise to a new and 
luxuriant growth of filaments; but it remained uncertain whether these initials 
came from coccus-cells which had retained their vitality, or from spores present in the 
solution. 
According to the statements of the pathologists’, which however require 
morphological proof, the Bacillus of anthrax introduced into an animal appears 
to vegetate there during its first period of growth, and during the first stages of the 
disease as shown by the fever-temperature, in the form of small round isolated 
cells or cocci; after some time it developes into the elongated rods which fill the 
blood-passages in the last stage of the disease. I did not find this statement con- 
firmed by my experiments with guinea-pigs ; in 20 hours after the introduction of 
spores into the skin I found an abundant growth of rods in the blood-vessels near 
the point of inoculation. 
This Bacillus shows no power of independent movement in any stage of its 
development apart from the slight oscillatory motions of doubtful origin which have 
been frequently observed during the first stages of germination. 
Bacillus subtilis (Fig. 195 2), known as the hay-bacillus from being commonly 
obtained from an infusion of hay, behaves much in the same manner as B. Anthracis 
when forming its spores; but its filaments are as a rule narrower, and when grown 
in largish quantities of fluid they are closely compacted together into a soft gelatinous 
pellicle covering the surface o{the fluid while its own upper surface is dry. If the 
plant grows vigorously in a comparatively narrow vessel, the surface of the pellicle 
becomes wrinkled and folded in consequence of the opposition offered to its surface- 
growth by the wall of the vessel. 
The formation of spores is exactly the same as in B. Anthracis; the ripe spore 
with the zone of the mother-cell which surrounds it is often somewhat broader than 
the cell was originally. 
It has been shown by Brefeld after a skilful examination of this species, that the 
outer wall of the spore, which is comparatively thick and continues to be highly 

1 See Roloff in Archiv f. Thierheilkunde, IX, Heft 6 (1883), p. 459. 
Hh 2 
