350 THALLOPHYTES 
and partly by the movements of animals with which they are 
associated. Their structural simplicity, power of resistance, and 
gelatinization of walls suggest a relationship to the Blue-green 
Algae. 
In connection with Bacteria another group of organisms, known 
as the Myzxobacteria, is commonly discussed. As the name sug- 
gests, the myxobacteria resemble both the Bacteria and Myxo- 
cytes. They differ from the Bacteria in that they form colonies, 
which in some cases are definite and elaborate in form. Some 
form colonies resembling a stalk bearing a group of sporangia at 
its summit. The life histories of the individuals of a colony are 
essentially the same as those of the Bacteria, differing chiefly in 
that the resting cells or spores form rod-like cells which escape 
and assemble to organize the colony. 
