400 BOTANICAL GAZETTE [JUNE 
reexamining fresh material of the other species of Myxobacter, 
in order to ascertain whether they exhibit similar modifications. 
The most important fact, which further examination of the 
sporiferous forms has served to determine, is connected with the 
process of spore formation and germination, matters which in my 
former paper were left in doubt from lack of exact observations ; 
certain appearances which one often sees in the rising masses 
of spores, having, in the first instance, led to the erroneous sug- 
gestion there made that they were produced in chains, while 
the process of their germination was also left undetermined. 
Further and more extended examination of these processes in 
pure cultures of Myxococcus rubescens shows that my previous 
conclusions in regard to these matters are not in accordance 
with the facts, since the phenomena in either case prove to be 
such as would naturally be associated with the development of 
organisms of this nature. 
As was mentioned in my previous account, sporulation 
_ appears invariably to take place gregariously, if one may use 
such an expression to indicate that isolated rods have never been 
seen to become thus transformed. The impulse to sporulate 
thus seems to be, as it were, contagious, and takes possession 
_of a large number of rods simultaneously, which, in their turn, 
exercise a similar influence on other rods in their more immedi- 
ate vicinity; so that a condition of things exists at this period 
which serves still further to accentuate the remarkable corres- 
pondence between the Myxobacteriacee and the Sorophoreae 
or pseudoplasmodium-forming Mycetozoa. From the fact, there 
fore, that sporulation only occurs in the rising rod mass, and 
| that it takes place more or less continuously, in a narrow zone = 
only, below the spore mass, which for a certain period is thus 
constantly being augmented from below, direct observation of 
the process, as for example in Van Tieghem cells, is almost uk 
_ impossible. It is therefore only by removing from pure cultures — 
and crushing whole guttulae that the successive stages can be — 
_ obtained. Both rods and spores are in general so minute ane 
_ become so promiscuously intermingled by this treatment that, 
