84. SIDNEY F. HARMER. 
than the younger ones. The roof of the ovicell connects the 
diverging zocecia, aud the cavity of the ovicell is clearly, in the 
central part of the colony, a space which completely surrounds 
a part of the zocecia. The roof of the ovicell is not perfectly 
even, but is formed of convex portions, shown in surface view 
in fig. 7. 
The ovicell increases in size during the growth of the colony ; 
and the nature of this increase may be understood from fig. 14. 
The marginal spaces, marked out by the vertical septa which 
start from the basal lamina, are all destined to give rise to 
zocecia, which are the only spaces which extend down to the 
base. The zoccium is first clearly indicated by the appearance 
of one or more of the spikes which occur on the upper margin 
of the orifice of all the zocecia. At about this stage (fig. 14, 4), 
one of the septa forming the side walls of the zocecium gives 
off a branch which runs more or less transversely. ‘The cavity 
of the young zocecium is in this way cut off from the cavity on 
the distal side of it. Up to this time the zocecium has been 
a short horizontally-placed tube, whose lower wall is part of 
the basal lamina, and whose free upper wall is parallel to the 
base. No sooner is the cavity of the zocecium completed on its 
distal side than it begins to alter its direction of growth. The 
woodcut Fig. 2 is a diagrammatic representation of the margin 
of acolony. The thick lines represent two young zocecia and 
ji 
8 e Se = : — C - - ‘ 
Fic. 2.—Diagram of the growth of the margin of the colony of Licheno- 
poraverrucaria. (For explanation, see text.) 
part of the basal lamina as they would be seen in a radial 
section, and the dotted lines represent the condition of the 
corresponding parts after a certain amount of growth has taken 
