118 SIDNEY F. HARMER. 
have seen that the suspensor is potentially a tube, and it 
appears to me that the cells of the suspensor lose the regularity 
of their arrangement, and that the embryo probably passes 
into the midst of the altered cells of the suspensor, perhaps 
by widening out the original lumen. There are, however, 
some reasons for thinking that the suspensor may be pushed to 
one side during the elongation of the embryo, and I cannot 
pronounce definitely on this point. In any case the suspensor 
ceases to be recognisable shortly after the close of Stage D, 
and the embryo invariably elongates so as to approach the 
fertile brown body with its distal or upper end. Towards the 
end of Stage E the embryo may have completely left its original 
follicle, and may lie entirely in the place of the original 
suspensor. 
I have found but few colonies (not more than seven or eight) 
in this stage ; but those few formed a series completely bridg- 
ing over the interval between Stages D and F. The length of 
four of these embryos was 30, 53, 70 (fig. 29), 72 u respectively. 
The average transverse diameter of the colonies measured in 
Stage E (seven cases) was ‘562 mm., the extremes being °48 
(‘77 long) and ‘62 mm. 
The embryophore shown in fig. 29 occupies a position in 
the zocecium exactly like that of the corresponding structure 
in fig. 27; that is to say, the cells surrounding the brown 
body are in contact with an invagination of the body-wall at 
the orifice of the fertile zoecium. The invagination is, how- 
ever, considerably deeper in the zocecium from which fig. 29 
is taken than in that shown in fig. 27. A thin layer of cells, 
not present in the earlier stage, now stretches across the mouth 
of the invagination from one edge of the rim of the zocecium 
to the opposite edge. 
I regard this layer as the remains of the calcareous film 
which occludes the mouth of the fertile zocecium (cf. pp. 86, 
87). The smallest entire colony in which occlusion was just 
commencing measures ‘77 mm. in transverse diameter, whereas 
the largest colony in Stage E (measured from sections) was 
‘62 mm. broad. This difference is quite unimportant, partly 
