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91
hinanden, sees en Spalte, der er Indgangen til nævnte
Hulhed. Fig. 6, d.
Huden, soin beklæder Furen, og som danner
Hulheden, er egentlig en Fortsættelse af Søstjernens Hud og
bestaar af 3 Lag: et ydre, strukturløst, Cuticula, Fig. 6, a,
hvori fine Kalkkorn ere enkeltvis leirede. et mellemste, det
egentlige Epithel. der dannes af Cylinderceller, og som er
betydelig fortykket over den omtalte Bindevævsliste paa
Læbernes frie Kand, samt Corium, der er fast. noget
tyk. og hvori findes Bindevævs- og Muskelfibre.
Hvor ingen saadanne Pedicellai’ier findes, er den
midterste Pig altid længere end Sidepiggene i Furen.
Foruden de ovenfor beskrevne Pedicellarier er hele
Bugfladens brede Interbrachialrum ligesom beklædt med
Pedicellarier, der staa temmelig tætte i regelmæssige
Rækker, have en oval Form og se for det blotte Øie ud som
skjælformede Papiller, Fig. 5. c. Disse Pedicellarier
bestaar ligesom hine af et Kalkskelet, der er omgivet af en
temmelig gjennemsigtig Hud, Fig. 8. 9. Skelettets
Basaldel er mere eller mindre rund, har en konkav Ledflade,
Fig. 8, a. 9, a, der svarer til en Forhøjning paa den
Bugplade, hvortil den er fæstet. Skelettets øvrige Del bestaar
af en sig opad udvidende, tyk Kalkplade, Fig. 8, b. 9. b,
paa hvis ene Rand iagttages en liden Fure, Fig. 9. c. 10,
lig den, der er omtalt hos de ’Pedicellarier, der sidde langs
Ambulacralfuren, kun ikke saa dyb og lang.
Huden, hvori Skelettet er indesluttet, er halv
gjennemsigtig og danner en Spalte, Fig. 8, c. 9, d. der svarer
til Kalkpladens Fure, og hvis tykke, hvælvede Læber, Fip.
8, d, kunne lukkes og aabnes, hvorved en lignende Hulhed
fremkommer som paa Bugfurens Pedicellarier; hvorvidt der
paa de nævnte Læber findes Cilier, kunne vi ikke afgjøre
med nogen Sikkerhed; men vi ere tilbøielige til at antage
en saadan Anordning. Den nævnte Hud bestaar af 3 Lag:
Cuticula, der er vandklar og strukturløs; Epithelet, der
dannes af meget langstrakte Cylinderceller, rige paa
Protoplasmaindhold, Fig. 8, e, samt af Corium, der danner et
fibrillært Bindevæv, hvori sees en stor Mængde
Bindevævs-legemer med mange Udløbere, der korrespondere med
hverandre, hvorved et smukt udbredt Net fremkommer. Yed
Basaldelen sees stærke Muskelbundter, der synes at
udgjøre selvstændige Muskler, som fæster sig just paa det
Sted, hvor Basaldelen gaar over i Kalkpladens
vingefor-mige Udvidning, Fig. 8, e.
Ogsaa paa Armenes Bugflade findes lignende
Pedicellarier; men her afvexle de med flade, lancetformige
Pigge.
cavity is formed, whose base is the furrow of the
cal-careous plate. If the labiæ are parted asunder, a fissure,
forming the passage to the above named cavity, becomes
visible (fig. 6, d).
The integument which covers the furrow, and forms
the cavity, is, in reality, a continuation of the integument
of the starfish, and it is composed of three layers, viz. an
exterior structureless layer, in which solitary, minute
calcareous grains (cuticula) are entrenched, (fig. 6, a) then,
a middle layer, or the real epithelium, formed of cylindric
cells, and considerably increased in thickness over the
connective-tissue fillet at the free margin of the labiæ, and,
finally, the third layer, or corium, which is firm, and
somewhat thick, and, in which, muscular and connective-tissue
fibres are found.
When no such pedicellariæ are found, the middle
spine is always longer than the lateral marginal spines of
the furrow.
Besides the above described pedicellariæ, the whole
actinal surface of the broad interbrachial surface, is also
clad with pedicellariæ, rather closely set in regular series.
These are ovate in form, and to the naked eye appear like
scale-shaped papillæ (fig. 5, c). These pedicellariæ, consist,
like the former, of a calcareous skeleton surrounded by a
rather translucent integument (figs. 8. 9). The basal part
of the skeleton, is more or less round, and has a concave
articulatory surface (fig. 8, a. 9, a) corresponding with a
prominence on the ventral plate, to which it is secured.
The rest of the skeleton, consists, of a calcareous plate (fig.
8, b. 9, b) which expands upwards, and upon one margin
of this plate, a small furrow occurs (fig. 9, c. 10), like the
one spoken of as pertaining to the pedicellariæ situated
along the ambulacra 1 furrow, only, not so deep, or long.
The integument which encloses the skeleton is
semi-translucent, and forms a. fissure (fig. 8, c. 9. d), which
corresponds with the furrow of the calcareous plate; and
whose thick tumid labiæ (fig. 8, d). may be closed and
opened, producing a similar cavity as in the case of the
ventral furrow’s pedicellariæ. Whither any ciliæ are to be
found on these labiæ, we are unable to state with any
degree of certainty, but we are disposed to assume, that there
is such an arrangement. The skeleton integument, consists,
of three layers viz. the structureless pellucid cuticle, then
the epithelium, formed of very elongated cylindric cells, rich
in protoplasm (fig. 8, e) and, finally, the corium, which forms
a fibrous connective-tissue, in which appear a multitude of
connective-tissue corpuscles, with numerous prolongations
coi’responding with one another, and producing, thus, a
beautiful expansive reticulation. Strong muscular bundles
are seen at the basal part, and appear to form
independent muscles, inserted, just at the point where the basal
part passes over into the wing formed extension of the
calcareous plate (fig. 8, e).
On the actinal surface of the rays, similar pedicellariæ
are also found, but they alternate, there, with flat
lancet-formed spines.
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