7° G O R G O N I A.
be called the perioftium ; for all along that fide o f thofe
tubes by which they adhere to the bony part, I could
difcover the pores very plainly from whence the juices
flow, that fupply it with proper materials to anfwer this
great end. It is to thefe longitudinal tubes, that the
bony parts o f thefe animals owe their ftriated or channelled
appearance, when they are ftript of their flefh, particularly
the red Coral, the verticillated Sea-Feather, and
many others ; but more remarkably in their kindred genus
the Ills, particularly that fpecies, called the Ills Hip-
puris, or black and white jointed Coral, as I fhall fhew
hereafter.
I fhall now proceed to relate the lèverai "©bfer va tions
that I have made on them, from time to time, and~~en-
deavour to anfwer the arguments that have been advanced
by late writers to prove their being of a mixt nature ;
that is, that they are animals, vegetating in the manner
o f plants with flowers, bark, and wood. As to their
firfl beginning, thefe animals produce their eggs through
their polype-like mouths, as I have fhewn in the diffec-
tion of the Alcyonium manus marina ; Phil. Tranf.
Vol. 53. tab. 20. fig. i i .
In all the fpecimens which I have received preferved in
fpirits, I have found eggs ; but after thefe eggs are produced,
the manner of their firfl: growing has only been
obferved by Donati, (fee Phil. Tranf. Vol. 47. pag. 104.
tab. 3. f i g .HIKL ) who examined them alive at the fea-
lide. He fays,
“ Whilft the firfl: cellule is fhut up, or the egg of the
“ Coral is in its fubftance, we do not find any one hard
“ part in it like bone or marble ; it is all foft : but af-
“ terwards, when the cellule opens, we begin to ob-
4t ferve fome hard lamella: j and when it is grown bigger,
“ and
64 and arrive at the height of about a line and a half (the
64 eighth part of an inch) it widens at bottom and at the
t£ top, and grows narrower in the middle, afluming the
“ proper confidence and hardnefs of coral ; and as this
“ grows, the polypi are multiplied, and new branches
“ of coral are formed.”' So that we fee, as foon as the
Polype from the eggftate. extends itfelf, and draws in
nourifhment, its hard part, or bone, appears even before
It is one-eighth of an inch high..
The Items then o f thefe animals, when they firfl grow
up, are always full of cells with their polypes, even down
to the bafe ; but as they advance towards their full ftze,;,
inftead of fo many polype mouths (in fome particular fpecies
j we find the flefhy part of the trunk and bafe com-
pofed of organs full of parallel connected tubes ; thefe
fpread themfelves downwards, over rocks or fhells in various
directions, drawing nourifhment from the polype
mouths above, to fecure the animal more firmly in its fta-
tion ; for from under thefe tubes, as in the ftem,- proceeds
and is formed a hard or bony part,' which adheres
moft ftrongly to the rocks, &c. and enables the animal to
refift the violence of the waves. As the tubes on the bafe
eonfift of the fame flefhy organical parts with thofe of
the ftem and branches, they muft undoubtedly receive
their fupply of animal juices from the nourifhment drawn-
in by the polype mouths above them : this will appear
clear to us, when we confider they are real Polypes, only
with the addition of a bony part: and it is well known
in experiments made on the Hydra, or frefh-water Polype,,
when it has many heads, that if one of them only is fed,,
all the reft will receive nourifhment, and grow ; that is,,
new heads will arife from the fides, and there will be a;
circulation of vital juices through the whole to the bafe,
3> which;