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53
udvidede det sig til en temmelig stor aflang Blære, fyldt
med vandklart Fluidum, Fig. 11. b, blev saa smalt og
rør-formigt igjen, forsynet med enkelte, yderst smaa Blærer,
og fortsatte saaledes sit Lob op til Kalkringen, hvorpaa det
fæstede sig. Fig. 11, c; det laa ganske frit, uden nogen
anden Forbindelse med Tarmen end ved dets tragtformige
Udvidning. Det venstre Ror udsprang ved Siden af det
høire, var yderst smalt, todelt og besat med enkelte smaa
Blærer; det laa frit i Kropshulheden. kun bundet til Huden
ved enkelte tine Traade, Fig. 11, d.
Hos et andet 20"" langt Individ vare heller ikke
Generationsorganerne at .opdage; men Rørene vare noget
mere udviklede. Det høire tog sit Udspring ligeledes fra
den sidste nedstigende Tarmslynges Væg ined en tragtformig
Udvidning, hvorved det tik Udseende, som om Tarmen paa
dette Sted var opheftet, Tab. VII, Fig. 10, a. Røret steg
nu opover, blev tyndere, og var besat med temmelig mange
smaa Blærer, indtil det fæstede sig paa Kalkringen, Tab.
VII, Fig. 10, b, c. Ikke alene den tragtformige Udvidning,
men ogsaa den smalere Del af Røret, ja endog flere Blærer
vare opfyldte med det samme Indhold, som fandtes i den
fuldproppede Tarm. Det venstre Rør udsprang i samme
Niveau, paa Tarmen, som det høire, et Stykke fra dette,
var kort, todelt, temmelig tykt, og forsynet med nogle
større og mindre Blærer. Saavel Røret, som samtlige
Blærer vare udfyldte af det lerede Tarmindhold, Fig. 10, d.
Hos ingen af disse smaa Individer var der nogen Kloak;
Tarmen gik lige ud til Halespidsen, og kun den yderste
Del var’ bunden ved nogle stærkere Muskelbaand til
Kroppens Vægge.
Paa disse Exemplarer viste det sig tydeligt nok, at
de forgrenede Rør egentlig ikke er andet end udbugtede
Forlængelser al’ Tarmen og høre denne til. Om noget
Aandedræt kan her ikke være Tale: thi de vare enten
ganske eller for en Del udfyldte af Tarmindholdet, som
bestod af en temmelig fast Lermasse, og som forklares
lettelig derved, at Aabningen fra Tarmen var særdeles vid.
den indtog næsten hele den ene Tarmvæg. Der kan
saaledes ikke være trængt Søvand op i disse Rør, og naar ikke
destomindre tiere Blærer vare fyldte af et næsten vandklart
Fluidum, saa hidrører dette visselig fra, at der foregaar en
Endosmose af Kropsva>dskeu.
Jo mere Individet er skredet frem i Udvikling, desto
smalere bliver den tragtformige Udbugtning. indtil den
endelig hos det ud voxne Dyr antager den tynde Rørform,
hvis Forbindelse med Tarmen da foregaar igjennem en
trang Aabning; nu tindes ikke i Rørene eller deres Blærer
noget af Tarmindholdet, men vel en næsten vandklar, lidt
klæbrig Vædske, tildels lig den. som indeholdes i
Kropshulheden, imedens Tarmen, hvorfra de have deres Udspring,
kan være aldeles tuldproppe’t. De fyldte Rør med deres
Blærer kunne saaledes ikke have deres Indhold fra ind-
ånd almost translucent; it soon however expanded into a
rather large, elliptic-shaped vesicle, tilled with a pellucid
fluid, flg. 11. b, became again slender and tubular,
exhibiting a few minute vesicles, and thus continued its course
to the calcareous ring, on to which it was webbed,
fig. 11, c; it lay quite free, having no connexion
whatever with the intestine save through the funnel-shaped
expansion. The left tube had its origin at the side of the
right, was exceedingly narrow, bipartite, and furnished with
a few . small vesicles; it lay free in the perivisceral
cavity, attached to the integument by- a few slender
filaments, fig. 11, d.
In another specimen, length 20"", the generative
or-• gans could not be detected; but the tubes where somewhat
more developed. As in the other example, the right tube
originated on the wall of the last descending convolution
of the intestine, and was furnished with a funnel-shaped
expansion, giving to the intestine the appearance of being,
as it were, hitched up at this point, Pl. VII, fig. 10, a. The
tube now began to ascend- and grow naiTOwer, exhibiting a
considerable number of vesicles, till it reached the
calcareous ring, to which it was webbed, Pl. VII. fig. 10. h, c.
Not only the funnel-shaped expansion, but also the
narrower portion of the tube, nay several of the vesicles even,
were full of the clayey substance found in the distended
intestine. The left tube hail its origin on the intestine, in
breast of the right, but some distance from it, was short,
rather thick, bipartite, and furnished with a few vesicles,
varying in size. Both the tube itself and all of the
vesicles were full of the clayey substance distending the intestine,
fig. 10, d. In none of these small animals was there a
cloacum; the intestine protended to the tip of the
caudi-forrn -extremity, the outermost portion only being webbed
to the walls of the body by a few strong muscular bands.
hi these specimens it was evident that, in a strict
sense, the ramose tubes are merely sinuous prolations of
the intestine. As to their performing a respiratory office,
that is quite out of the question; for they were either wholly
or partially distended with the compact, clayey substance
forming the contents of the intestine, which is readily
explained by the fact of these ramose tubes passing into the
latter through a remarkably wide opening, which occupied
nearly the whole of one of the intestinal walls. Hence
water cannot possibly be forced up into these tubes; true,
several of the vesicles contained an almost limpid fluid;
but "an endosmose of the perivisceral fluid is sufficient to
account for that.
The more advanced the stage of development attained
by the animal, the more slender does the funnel-shaped
expansion become, till, in full-grown individuals, it assumes
the slender, tubular form, its connexion with the intestine
being then effected through a narrow opening. Now, neither
the tubes themselves nor their vesicles contain any of the
substance that fills the intestine, but an almost pellucid,
viscous fluid, bearing some resemblance to that in the
perivisceral cavity, whereas the intestine, on the walls of which they
originate, is sometimes wholly distended with focal matter.
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