XI 
wail openings are always left that communicate with 
the external waters, that the polypi within may be 
continually supplied with aliment, and the principal 
materials for the construction of their habitations. 
The navigator confidently sailing in a sea that his 
predecessors have indicated as free from rocks, dashes 
his prow on an unexspected shelf, whose sides are 
so perpendicular, that at his stem no sounding can 
be found ; and when combating with the fury of the 
tempest he meets one of these openings which chance 
or the instinct of the polypi have left unclosed, he 
enters a harbour of slightly undulating waters, 
sheltered from the contending storms, which without 
the barrier seem bent on its annihilation, but cannot 
shake it. 
The Polypidoms do not always rise to the surface 
of the waters ; some extend themselves horizontally 
on the base of the sea, or pursue its curvatures, and 
spread Ocean’s floor with an enamelled carpet of va- 
ried and brilliant colours; at other times this carpet 
has only one shade, almost equalling the Tyrian purple 
of antiquity. Many of these beings resemble a bush 
that winter has despoiled of its leaves, but which 
spring has renovated with fresh flowers ; and attract 
by the beauty of the petalcd animals with which their 
branches are covered from the base to the extremities. 
