916 The American Naturalist. [November, 
are about 14 in length, while their breadth does not exceed 4 
or å of this size. Each rod produces only one spore. If these 
spores are allowed to dry on the glass where they have been 
formed, they may be kept for a long time, and subsequently 
on placing them in a nutrient liquid the development of new 
bacteria may be observed. At the time of germination, which 
is hastened the same as sporogenesis, by an increase of tem- 
perature, the spore begins to swell and its cylindric form — 
changes to an ellipsoid. The strongly refractive power is also 
gradually lost, the middle of the spore first becoming dull 
while the brilliant gleam still persists more or less at the two 
extremities (34, pl. I, figs. 2 and 3). Here we have the condi- 
tion which must be considered as the commencement of ger- 
mination. The wall is split into two portions, which remain 
united at one side. The central part of the spore from which 
the refringence has entirely disappeared, is the place where the 
two halves of the spore open one from the other, and here a 
baculiform body of slight refringence was observed pushing out 
(pl. I, figs. 4 and 5). During the growth of this body the sheen 
also diminishes very greatly at the two extremities of the 
spore, and soon there is a state which cannot be indicated 
better than by likening the germinating spore to a hammer, 
the two portions of the wall of the spore representing the head 
while the handle is formed by the rod which has issued from 
the spore (fig. 6). Often after a longer or shorter time, the rod, 
one end of which is squeezed between the two parts of the wall 
of the spore, begins an oscillatory movement, and thus succeeds 
in freeing itself, whereupon it moves through the liquid in the 
manner common to bacteria, the empty wall being left behind 
(fig. 6c). In other cases, after escaping from the spore, the 
young bacterium remain motionless in front of the empty wall 
for a long time beforeswimming away. Finally, the rod some- 
times drags the empty wall after it (fig. 8). In all cases the 
rod which has escaped is an ordinary bacterium which soon 
divides in the manner already described.” 
The author never found spores in the living hyacinth. 
This, he says, accords with de Bary’s observation on Bacillus 
anthracis, he having never found spores in the living animal. 
