130 PHYSIOLOGY OF THE BACTERIA. 
there is formed in each article so nourished a 
spherical or ovoid spore, homogeneous, highly 
refractive, having a dark outline. At the same 
time, the protoplasm which occupies the rest of 
the cavity disappears little by little, and is re- 
placed by a hyaline liquid, which separates the 
spore from the membrane; this dissolves in its 
turn, and finally the spore is set at liberty. If the 
article is swollen in tadpole shape, it is in the ter- 
minal swelling that the spore has birth; if it is 
spindle-shaped, it is near the middle ; if it is cylin- 
drical, it may be at any point whatever, but is 
usually near one extremity. ‘The spore when set 
free germinates under favorable circumstances. 
At a point where its circumference becomes pale, 
it gives out a little tube slightly more slender 
than itself, which elongates rapidly and divides. 
This fourth period of development or germinative 
phase brings us back to our point of departure.” 
Sporangia. — Finally, not only do the bacteria 
develop spores in the interior of their filaments, 
slightly modified in form, but we may also observe 
the formation of a veritable sporangium contain- 
ing many spores. The unpublished observations 
of M. Touissant, Professor of Physiology in the 
Veterinary School of Toulouse, give this result, 
which he has kindly communicated to me. 
In cultivating spores of the bacteria of charbon 
in the serum of the blood of the dog, under the 
microscope, in the warm chamber of Ranvier, 
Toussaint has seen the filaments take a transverse 
