390 The Botanical Gazette. [December, 
ation as a distinct order seems unavoidable. To the mem- . 
bers of this order the writer proposes to give the name 
MYXOBACTERIACE&, for reasons which will become apparent 
if we consider for a moment the more important stages in 
their development. 
{t should first be noted that the life history of these organ- 
isms shows a distinct and more or less regular division into 
two periods; a period of vegetation and, under favorable 
conditions, a period of fructification or pseudo-fructification: 
but while the first period is essentially similar in all the forms 
observed, the second presents remarkable variations. 
In the first instance a swarm or collection of rod-like 
bodies, derived from the successive division by fission of one 
or more primary individuals, always distinct from one an- 
other, possessing a power of slow locomotion and secreting 
as they multiply a firm gelatinous base which connects the 
colony as a whole, constitutes the vegetative condition of the 
organism. This vegetative state continues for a variable but 
distinct period of time, and in the different forms is charac- 
terized by slight variations in the grouping of the individuals 
composing it. In some cases these may be collected in radi- 
ating strands or concentric ridges, or again may be distrib- 
uted evenly throughout the colony, which in all cases, when 
growing on a solid medium, possesses a clearly defined ad- 
vancing edge or border, produced by a heaping up of active 
individuals in this position. The colony continues to extend 
itself in this fashion while the conditions remain favorable for 
its growth; but in the meantime the individuals within this 
advancing border, having increased rapidly by fission for a cef- 
tain period, begin to swarm together at different points, often 
with a characteristic circular tendency in their motion. This 
piling up of individuals at definite points marks the begi” 
ning of the second period just mentioned, which has for 
In the simpler forms, these masses, having raised me 
tions, become rounded off and may be directly encys'© 
without further differentiation. A gelatinous envelope ae 
unfavorable conditions for a protracted period. — en 
From such a simple type as that just described the 10 
dee 
