274 Scientific Intelligence. 
~ —— and above, hear = these tubes bend towards this 
avity, t passes around so as to form a circle, about the 2 
pars of the zh miferous system or near the centre of the disk. Ther 
is thus a marginal, and (if there be no mistake as to its nervous chee 
acter,) a central circle to the nervous system; from the latter at a point J 
alf way between two chymiferous tubes a branch passes off and de- 5 
‘scends to the buccal or digestive mass below, and other branches go to 
the inner muscles. Professor Agassiz observes that there is a differ- 
ence between the cord of the lower margin and the other threads, and : 
e was not fully satisfied of the real nature of the latter. Instead of 
consisting of distinct cells, they are thin threads in which the cellular 
+ appearance is almost gone, excepting where they combine to form a 
mai ved i 
fact, and also their connection with the chy miferous tubes and the 
sensitive bulbs below,—the nature and position of the plexuses as well 
as pei branching to. the digestive organ and to the muscles—favor 
the v taken. The close juxtaposition of the " dhipeitattde system 
athe source of nutriment—with the nervous system and the sensitive 
bulbs and, eye-specks, is remarked upon as a fact of much interest. 
weal 
nage than of fibres.’ Over the surface of the bell-shaped part of the 
k, the epithelium consists of Arenas polygonal cells,. of very faint 
Cealaies hardly distinguishable except by a kind of mosaic arrangemen 
seen by means of their gra amar contents. ti the sides and above the 
eres 
eS 
sigh 
tractile cells, beneath the epithelium extend in two-main“diree- 
the main bundles being vertical, four in Eotnbek and alterna- 
ith thieehyreifarane tubés ; and the others transverse. circular, in 
with others smaller and:.léss ular. — 
ra 
shocks by twos, with belie four. This seaPeaiy) has a anwar 
layer. of contractile cells lining the whole interior, as was di istinctly ob- — 
served on close examination. It properly consists of four parts, @% 
one chymiferous tube to another.» There is still another 
a angles sie most’ numerous about ‘the eye-spec cks,' yay iat 
: dow. well known t these Meduse-in one stage of +t eir.exist: | 
sea | olyp fm et e ovly, 
d these. Hydroid polyps are theres 
rsia ‘in one of its: conditions is a! 
vnin g fo.the Sarsia — a 
pttenis' of th mals i 
