128 SIDNEY F. HARMER. 
approaching an end, from the fact that the ovicell is small and 
the embryophore is compact and unbranched. 
Some colonies in Stage G which have no polypides, or only 
one or two polypides, appear quite healthy. It is probable 
that in these cases the production of embryos would have soon 
been injuriously affected, as a single polypide is probably 
insufficient for the nutrition of a whole ovicell full of embryos. 
This probability is increased when it is noticed, as is commonly 
the case, that many of the remaining polypides have quite 
recently degenerated ; showing that the colony has had a full 
complement of polypides up to a very recent period. 
The interdependence of the development of the embryos and 
the nutritive conditions of the whole colony is, however, no- 
where more clearly shown than in the very remarkable fact 
that a large proportion of the older colonies have no brown 
bodies at all. A brown body is of course present in a zocecium 
which has lost its polypide altogether, without developing a 
bud to replace it. But most of the zoccia in a healthy colony 
—during Stage G, for instance—contain a polypide without 
any brown body. In the earlier stages, where the mass of 
embryonic tissue present in the colony is very small, polypides 
can degenerate, and new buds can develop to take their place 
without materially affecting the health of the colony. And as 
a matter of fact we do find that most young colonies contain 
polypides, degenerating polypides, fully formed brown bodies, 
and young polypide-buds, which are developing to take the 
place of the old polypides. 
Were any extensive degeneration of the polypides to take 
place in any colony containing numerous embryos, it is 
probable that the colony could no longer bear the strain of 
producing its embryos. In a large proportion of the colonies 
in Stage G, there is no trace of the complete degeneration of 
polypides, there are no brown bodies, and there are no polypide 
buds, either in new zoccia or in old ones. Even the increase 
of the size of the colony, by the formation of new zocecia, thus 
appears to be retarded during the height of the formation of 
secondary embryos. 
