402 BOTANICAL GAZETTE [ JUNE 
becomes so thick that the whole spore remains bright and refrac- 
tive and impenetrable by stains, except after they have acted for 
a considerable time. 
The occurrence of this nucleus-like body in the spores of 
Myxococcus led me to examine more carefully the conditions 
found in the rods of Chondromyces while becoming encysted, 
and in these instances also the granular more deeply staining 
portions of the cell contents were found to collect in more or 
less definitely circumscribed masses. In Chondromyces this 
mass, though more frequently single, was found to be generally 
elongate, occupying a central or usually somewhat lateral 
position (fig. 75). In the rods which compose the ascending 
‘‘pseudoplasmodium” in this genus, the granular masses are 
very readily demonstrated by staining, and have in general the 
appearance represented in fig. 74, a small mass being commonly 
distinguishable at either end of the cell, while a much larger and 
more irregular one is apt to occupy a central position. In Cysto- 
bacter fuscus, on the other hand, a portion of the more deeply 
staining contents, as has been previously mentioned, was found 
to become definitely aggregated into a well defined nucleus-like 
body corresponding exactly in its general appearance to that of 
the sporulating forms just described, an accompanying thicken- 
ing of the wall being in many cases distinctly visible. 
Such transitions between a slight and a complete transfor- 
mation in the rods at the period of fructification are doubtless 
correlated with an inverse differentiation of the cyst, the most 
perfectly formed spores being those characteristic of deliquescent 
guttulae, while the least well marked differentation of the 
individual rods occurs in forms like Chondromyces crocatus in 
which the cysts reach a maximum development. : 
At the time when my first notes were published no satis~ 
factory data had been obtained in regard to the germination of 
the spores in any case. In cultures of Myxococcus made from 
material which had been kept air dry for several months, the 
spores when placed ina nutrient medium gradually assumed 4 
short stout rod form; but no separation of this body from the 
