52 
gangliose Masse udgaar igjen overordentlig fine | 
Nervefibre til ethvert af de her feestede Vedheng. 
Synsnerverne (Fig. 4, 0) danner til hver Side en 
steerk, lige udad gaaende Stamme, der, efterat veere 
traadt ind i Mienstilkene, svulmer nd til et kolbe- 
formigt Synsganglion. Dette (se Fig. 6) er ved en 
transversal Indsnoring delt i 2 paa hinanden fol- 
gende Knuder eller Segmenter og udsender fra sin 
noget skjevt afrundede Ende talrige divergerende 
Nervetraade, der passerer til de enkelte Synselemen- 
ter. Ethvert af disse sidste er (se Fig. 7) isoleret 
ved en cylindrisk Skede, i hvis indre den saakaldte 
Synsstav sees som en fint tverstribet Axe (c), streek- 
kende sig mod Peripherien af Qiengloben, hvor den 
forbinder sig med en kegleformig fastere Del, den 
saakaldte Krystalkegle (b). Denne er omgivet af 
et morkeredt Pigment og ender med et sterkt lys- 
brydende, lindseformigt Legeme af ellipsoidisk Form 
(a). Den GWiengloben omgivende ydre Hud (cornea) 
er ganske glat, uden Spor af Facetter. . 
Kjonssystemet. — Han- og Hun-Organerne for- 
holder sig meget ulige, saavel hvad Bygning som 
Beliggenhed angaar, og maa derfor beskrives ser- 
skilt. 
Ovarierne (se Tab. VI, Fig. 3 og 4, Tab. VIII, 
Fig. 11) strekker sig i Form af 2 smale cylindriske 
Sekke igjennem Storsteparten af Truncus, til hver 
Side af og noget nedenunder Tarmen. Deres for- 
reste Ende er omtrent beliggende ved Grendsen af 
Ade og 5te fodberende Segment; den bagerste Ende 
strekker sig ind i selve Kjonsringen. Derimod fin- 
des ingen Del af Ovarierne i selve Bagkroppen, saa- 
ledes som Tilfeeldet er hos Slegten Branchipus. I 
nogen Afstand fra deres bagre Ende udgaar fra 
hvert Ovarium nedad en kort og tyk Agleder, der 
udmunder i Basis af Aggesekken. glederne er 
delvis omhyllede af en voluminos Kjertel, der af- 
sondrer Stoffet til Aiggeskallen. I Ovariernes Indre 
findes som oftest kun en enkelt Rekke af sig ud- 
viklende Ag (se Tab. VIII, fig. 11), med gronagtig 
Blommemasse og mere eller mindre tydelig Kim- 
blere. A ggene synes at udvikle sig fra den forre- 
ste Ende af Ovarierne, da her findes sammenhobede 
en hel Del smaa Celler. Fra Ovarierne passere 
Eggene, efterhvert som de modnes, ind i den sek- 
formige Matrix, hvor de omgives med sin Skal. 
Denne er temmelig fast og tyk, og viser sig i Tver- 
snit tydeligt dobbelt kontureret. gindholdet er i 
de fleste Tilfeelde uniformt, fintkornet, uden tydelig 
Kimblere (Fig. 14). I enkelte Tilfeelde (Fig. 13) 
syntes Klovningsprocessen allerede at vere begyndt, 
da Agindholdet var delt i 4 skarpt begrendsede 
Segmenter. 
ganglionic mass at the end of the antenna. From 
this ganglionic mass again, exceedingly delicate 
nerve-fibres run out to each of the appendages there 
attached. 
The optic nerves (fig. 4, 0) form, on each side, a 
strong stem going straight out, which, after having 
entered the eye-stalks swells out to a club-shaped 
optic ganglion. This (see fig. 6), by a transverse 
constriction, is divided into 2 successive dilatations 
or segments, and sends out, from its somewhat obli- 
quely rounded end, numerous divergent nerve-fila- 
ments, which pass to the several visual elements. 
Each\ of these is isolated by a cylindrical sheath 
(see fig. 7) in the interior of which the so-called 
optic rod is visible in the shape of a finely trans- 
versely striped axis (c) extending towards the peri- 
phery of the eye-ball, where it unites with a firmer, 
conical part, the so-called crystalline cone (b). The 
latter is surrounded by a dark-red pigment, and ends 
in a strongly refractive lentiform body, ellipsoid in 
shape (a). The skin (cornea) surrounding the eye- 
ball is quite smooth, without a trace of facets. 
Generative system. — The male and female 
organs are very dissimilar, both as regards struc-— 
ture and position, and must therefore be separately 
described. 
The ovaries (see Pl. VI, figs. 3 and 4, Pl. VIII, 
fig. 11) extend in the form of 2 narrow cylindrical 
bags through the greater part of the trunk, on each 
side of, and a little below the intestine. Their an- 
terior end lies almost at the boundary between the 
4th and 5th pedigerous segments; the posterior end 
extends into the genital segment itself. On the 
other hand, no part of the ovaries is found in the 
posterior part of the body, as is the case in the 
genus Branchipus. At some distance from their 
posterior ends, a short, thick oviduct issues from 
each ovary, passing downwards, and opening into 
the base of the ovisac. The oviducts are partially 
enveloped by a voluminous gland which secretes 
the substance for the shell of the egg. In the inte- 
rior of the ovary there are found, as a rule, only a 
single row of ova in process of development (see Pl. 
VIII, fig. 11), with a greenish yolk-mass, and more 
or less distinct germ-vesicles. The ova appear to 
be developed from the anterior end of the ovaries, 
as a number of small cells are here found crowded 
together. Each egg, as it matures, passes from the 
ovary into the sac-like marsupium, where it is en- 
veloped in its shell. This is tolerably firm and 
thick, and in transverse sections shows a distinct 
double outline. The contents of the ova are, in 
most cases, uniform, finely granular and without 
distinct germ-vesicles (fig. 14). In one or two cases 
(fig. 14), the cleavage process seems to have already 
begun, the contents of the ovum being divided into 
4 sharply-defined segments. 
ee ee ee 
