en Mængde Sidegrene til Tarmen, hvortil det er bundet 
ved. Bindeveey. 
TImellem Ryg- og Bugkarret er i Tarmvæggene et 
intermediært Karnet, hvorved de anastomosere med hinan- 
den. Hvor disse to Hovedkar tage deres Udspring, der 
dannes af de yderst fine Kar, hvormed de tog deres Begyn- 
delse, et Karkomplexus, som omgiver Tarmen. Fra dette 
Karnet synes at udgaa Mayens saavel Ryg- som Bugkar. 
Vi sige synes; thi saa har det forekommet os paa de Præ- 
parater, vi have havt'til vor Raadighed, omendskjont dette 
ikke stemmer overens med Sempers Angivelser, der støtte 
sig til flere vellykkede Injectioner, og som gaa ud paa at 
bevise, at der ingen direkte Forbindelse er imellem Mavens 
og Tarmens Blodkar. 
Rygkarret er temmelig fint, men bliver tykkere opimod 
-Ringkanalen, hvor det afgiver en Gren til denne, efterat 
det tidligere har, sendt flere Grene til Kjønsorganerne. 
Fra Rygkarret udgaar en Mængde Tvergrene, som forbin- 
des med korte perpendikulære Smaagrene, hvorved et smukt 
Maskenet med store aflange paatversliggende Masker frem- 
kommer. : 
Bugkarret forholder sig ganske paa lignende Maade, 
og danner ligeledes et stormasket Net, der anastomoserer 
med Rygkarrets, saa at Maven er omspændt af et rigt 
Karnet, Tab. VII, Fig. 8, 7. Hvorvidt Karret til Ring- 
kanalen gaar ind i denne, saa at Blodet blander sig med 
dens Indhold, kunne vi ikke afgjore. 
Fra de forreste Ender af Mavens Ryg- og Bugkar 
danner sig en rig Karfletning, der ligger under Ringkanalen 
og omgiver Svælget; det er dette Karplexus, som Semper 
kalder Svælgkruset. Denne ringformige Karfletning udsen- 
der en Mængde baade op- og nedstigende Grene til Svælget, 
hvor de danne et udbredt Karnet. Desforuden forsyner 
den Stenkanalen og den Poliske Blære med Kar. 
Nervesystemet. 
Nerveringen ligger tæt under Mundskivens Hud, 
indenfor Kalkringen, og omgiver Svælget, bundet til dette 
ved tynde Bindevævstraade. Den er temmelig bred, om- 
trent dobbelt saa bred, som hver af de 5 fra den udgaaende 
Radialnerver, og har en straagul Farvé. Den dannes af 
et ydre cellet Lag (Skeden) og et indre, som er mere kom- 
pakt, og hvori ingen Celler var at opdage. Fra Nerve- 
ringen udgaa mange fine Grene, saavel til Svælget som til 
Mundskivens Hud og til Tentaklerne, samt 5 store: Grene, 
der danne Radialnerverne. Disse ere ved deres Udspring 
60 
the extremity of the rectum. It diminishes considerably 
in, thickness on the inferior descending portion of the 
intestine, fig. 3, 7, but sends off a large number of subsi- 
diary branches to the intestine, to which it is webbed by 
connective tissue. i 
Between the dorsal and the ventral vessels, in the 
walls of the intestine, extends an intermediary vascular net- 
work, whereby the said vessels are made to anastomose one with 
the other. Where these two vessels have their origin, the 
minute vessels from which they issue constitute a vascular - 
plexus, surrounding the intestine. In this vascular net- 
work originate apparently the dorsal and ventral vessels of - 
the stomach. We say apparently; for so it seemed to us. 
when examining the prepared specimens on which our ob-. 
servations. were made, though such an assumption does 
not agree with Semper's statement, which is based on the 
result of: divers successful injections, undertaken to prove. 
that no direct connexion -exists between the blood-vessels 
of the stomach and those of the intestine. 
The dorsal vessel is rather slender, but increases 
in thickness near the annular canal, whence a branch pro- 
ceeds to the latter, several ramifications having been previ- 
ously sent off to the generative organs. From the dorsal 
vessel proceed numbers of transversal branches, interlaced 
with short perpendicular branchlets, thus producing a grace- 
ful network, with large, elliptic-shaped, transversely ar- 
ranged meshes, 
. The same applies to the ventral vessel, which also 
forms a wide-meshed net, anastomosing with that of the 
dorsal yessel, so that the stomach is completely invested 
with vascular network, Pl. VII, fig. 8, 7. Whether the 
vessel proceeding to the annular canal open into that organ, 
enabling the blood to mingle with its contents, we could 
not determine. 
From the anterior extremities of the dorsal and ven- 
tral vessels of the stomach, a vascular plexus, surrounding 
the æsophagus, extends under the annular canal; to this vascu- 
lar network it is, that Semper has given the name of “phar- 
yngeal curl.” This annular plexus of vessels sends off 
large numbers of ascending and descending branches to the 
esophagus, where they constitute an extensive vascular 
network. It furnishes, too, the sand-canal and the vesicle 
of Poli with vessels. 
Nervous System. 
The nervous ring is placed immediately beneath the 
muscular tunic of the oral disk, within the calcareous ring, 
and surrounds the cesophagus, to which it is webbed by 
slender filaments of connective tissue. ” It is rather broad, 
— about twice as broad as the 5 radial nerves. pro- 
ceeding from it, and is of a light straw-colour. It consists 
of an outer cellular layer (the sheath) and of an inner 
layer, more compact in texture, in which no cells could 
be detected. From the nervous ring proceed numerous 
slender branches, not only to the cesophagus, but also 
