34 PLANT LIFE 
by fission. This is betrayed by their aggrega- 
tion in pairs and groups of cells which have 
obviously sprung from a single parent. But 
an interesting and important feature of their 
development consists in the fact that, after 
Fig. 2.— Apiocystis Brauniana. I.—Mature Plant. 
I1.— Younger Plant. G, The gelatinous outer layer of the 
membrane. 
they have been formed, they can modify 
their positions. Thus all of them come to lie 
just beneath the periphery of the jelly, and 
are not uniformly distributed through it as 
might have been expected. This arrange- 
ment is one which secures evident advantages 
from the point of view of suitable illumination. 
