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37
Man kan gjøre sig et Begreb om hvor tynd Tarmens
Vægge var, naar vi sige, at det var en Stund, vi troede
der ingen Tarm var, da denne var løsreven fra Rectum;
men at hele Dyrets Bagdel udgjorde en Sæk for
Excre-menterne. Ved stærk Loupe kunde man dog imellem hver
Bolus se en flortin Hinde, der var Tarmvæggen.
De særegent formede Excrementer dannes
sandsynligvis idet Føden passerer Spiserørets bagre udvidede Del
(Maven); thi lige der hvor denne gaar over i den egentlige
Tarm laa en Bolus, imedens der i Spiserøret kun var den
lerholdige Sand, hvori fandtes en Mængde Foraminiferer.
Centralnervestrængen løber som en tin gulhvid Traad,
Fig. 4, b, langs den uigjennemsigtige forreste Kropsdels
Midte, under Spiserøret, og følger dette til dets forreste
Ende, hvor den slaar sig om Svælget og sandsynligvis
danner en Ring. Paa denne Vei afgiver den mange Sidegrene
til Spiserøret og Huden.
Det er ikke alene Hudens Muskler, der forsynes med
Grene, men mange af disse forlænge sig igjennem
Bindevævet ud i Epithelet lige under Cuticula, hvor de fine
Ender dels tabe sig imellem Cylindercellerne, dels gaa over
i aflange, næsten kølleformige Legemer, der ere forsynede
med en - stor Kjerne, og som vel maa betragtes som
Organer, der staa i Følelsens Tjeneste, Fig. 5, /. Disse, fine
peripheriske Nervegrene danne i deres Løb smaa
ganglie-formige Knuder, som have en stor Kjerne omgivet af
Protoplasma, Fig. 5, g, og fra hvilke udgaa snart en, snart flere
Grene, der hyppig anastomosere med tilsvarende Grene fra
andre Ganglier.
Det er ikke lykkedes os, trods al anvendt Møie, at
forfølge Centralnervestrængen længere bag i den glasklare
Sæk, eller paa Tarmen, ihvorvel det er sandsynligt, at den
langs Sækkens indre Flade strækker sig bag imod Rectum.
Kjønsorganerne bestaa hos vort Individ af
Æggestokken og en Æggebeholder (Uterus). Æggestokken ligger
langs Centralnervestrængen, Fig. 4, c, og tager sin
Begyndelse et Par Millimeter bagenfor Mundaabningen. Den
dannes egentlig af en Fold af det Mesenterium, som binder
Svælget til Kropsvæggen og ender noget bagenfor den
glasklare Kropsdels Begyndelse.
Æggestokken er sammensat af en stor Mængde næsten
pæreformige Follikler, Fig. 8, der bestaa af en klar
Membran, hvori sees Bindevævslegemer, Fig. 8, a, og hvis indre
Flade er beklædt med store Celler, Fig. 8, b. I den
smalere Del af Follikelen saaes et begyndende Æg, omgivet
ligesom af en Krands Celler. Vi saa kun Antydninger til
Æg i Folliklerne.
Efter alt at dømme foregaar Æggets Udvikling paa
It will give some idea of the extreme thinness of the
intestinal walls, that we were actually in doubt at first
whether there was an intestine (it had been detached from
the rectum), conceiving the whole posterior portion of the
animal to constitute a receptacle for the fæces. With a
strong magnifier could be just distinguished between the
boli a gauzy pellicle, — and this was the wall of the
intestine.
Probably the peculiar form into which the fæces are
moulded, may be traced to the passage of the food through
the posterior distended portion of the oesophagus (the stomach);
for, exactly where that organ passes into the intestine lay
a bolus, the contents of the oesophagus consisting exclusively of
argillaceous sand, in which were numbers of Foraminifera.
The central nervous chord protends as a slender
yellowish-white filament, fig. 4, b, along the middle of the
anterior opaque portion of the body, underneath the oesophagus,
accompanying that organ to its anterior extremity, where
it winds round the gullet, forming probably a ring. On
its course it sends off numerous subsidiary branches to the
oesophagus and the skin.
Not only is it the muscles of the skin that are
furnished with branches, — many of these offshoots, piercing
the connective tissue, pass on into the epithelium,
immediately beneath the cuticle, where their delicate extremities
either coalesce with the cylindric cells, or expand into
elliptic, more or less clavate corpuscles, furnished with a
large nucleus, and which may, we think, be regarded as
organs subservient to the sense of touch, fig. 5, f. These
slender peripheral nervous branches form on their course
numerous ganglionous nodules, with a large nucleus
embedded in protoplasma, fig. 5, g, and from which proceed one
or more branches, that frequently anastomose with
corresponding branches from other ganglions.
We have failed, notwithstanding a most careful
microscopic examination, to trace the central nervous chord
farther back in the hyaline sac, or on the intestine, though
it probably passes along the inner surface of the sac
towards the rectum.
The generative organs consist in our specimen of the
ovary and one uterus. The ovary protends along the
central nervous chord, fig. 4, c, and takes its origin a
millimetre or two posterior to the buccal aperture. It
consists properly of a fold of the mesentery that webs
the gullet to the wall of the body, and terminates a little
posterior to the commencement of the hyaline portion of
the body.
The ovary is built up of large numbers of almost
pyriform follicles, fig. 8, consisting of a translucent membrane,
in which are seen corpuscles of connective tissue, fig. 8, a,
and whose inner surface is covered with lai’ge cells, fig. 8, b.
In the narrower portion of the follicle, was seen a
rndi-mentary egg, surrounded by a cincture, as it were, of cells.
We saw none but incipient ova in the follicles.
Judging from analogy, there is every reason to believe
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