52 



gangliose Masse udgaar igjen overordentlig fine 

 iSfervefibre til ethvert af de her fsestede Vedhæng. 



Synsnerverne (Fig- 4, o) danner til hver Side en 

 stærk, lige ndad gaaende Stamme, der, etterat være 

 traadt ind i Øienstilkene, svulmer nd til et kolbe- 

 formigt Sj'nsganglion. Dette (se Fig. <j) er ved en 

 transversal Indsnøring delt i 2 paa hinanden fol- 

 gende Knnder eller Segmenter og udsender fra sin 

 noget skjævt afrnndede Ende talrige divergerende 

 Nervetraade, der passerer til de enkelte Synselemen- 

 ter. Ethvert af disse sidste er (se Fig. 7) isoleret 

 ved en sylindrisk Skede, i hvis indre den saakaldte 

 Synsstav sees som en fint tværstriliet Axe (e), stræk- 

 kende sig mod Periplierien af Øienglohen, hvor den 

 forbinder sig med en kegleformig fastere Del, den 

 saakaldte Krystalkegle (b). Denne er nmgivet af 

 et niørkerodt Pigment og ender med et stærkt lys- 

 brydende, lindseformigt Legeme af ellipsoidisk Form 

 (a). Den Hiengloben omgivende ydre Hiid (cornea) 

 er ganske glat, nden Spor af Facetter. 



Kjønssystemet. — Han- og Hnn-Organerne for- 

 holder sig meget nlige, saavel hvad Bygning som 

 Beliggenhed angaar, og maa derfor beskrives sær- 

 skilt. 



Ovarierne (se Tab. VI, Fig. 3 og 4, Tab. VIII, 

 Fig. 11) strækker sig i Form af 2 smale eylindriske 

 Sække igjennem Størsteparten af Trnnons, til hver 

 Side af og noget nedenunder Tarmen. Deres for- 

 reste Ende er omtrent beliggende ved (Tiændsen af 

 4de og 5te fodbærende Segment; den bagerste Ende 

 strækker sig ind i selve Kjonsringen. Deriniod tin- 

 des ingen Del af Ovarierne i selve Bagkroppen, saa- 

 ledes som Tilfældet er hos Slægten Bravcliipiis. I 

 nogen Afstand fra deres bagre Ende ndgaar fra 

 hvert Ovarinm nedad en kort og tyk Ægleder, der 

 udmunder i Basis af Æggesækken. Æglederne er 

 delvis omhyllede af en voluminøs Kjertel, der af- 

 sondrer Stoffet til Æggeskallen. T Ovariernes Indre 

 tindes som ofte.st kun en enkelt Række af sig iid- 

 viklende Æg (se Tab. VIII, fig. 11), med grønagtig 

 Blommemasse og mere eller mindre tydelig Ivim- 

 blære. Æggene s3-nes at udvikle sig fra den forre- 

 ste Ende af Ovarierne, da her findes sammenhobede 

 en hel Del smaa Celler. Fra Ovarierne passere 

 Æggene, etterhvert som de modnes, ind i den sæk- 

 formige Matrix, hvor de omgives med sin Skal. 

 Denne er temmelig fast og tyk, og viser sig i Tvær- 

 snit tydeligt dobbelt kpntureret. Ægindholdet er i 

 de fleste Tilfælde uniformt, fintkornet, nden tydelig 

 Kimblære (Fig. 14). I enkelte Tilfælde (Fig. 13) 

 .syntes Kløvningsprocessen allerede at være begyndt, 

 da Ægindholdet var delt i 4 skarpt begrændsede 

 Segmenter. 



ganglionic mass at the end of the antenna. From 

 this ganglionic mass again, exceedingly delicate 

 nerve-fibres run oiit to each of the appendages there 

 attached. 



The optic nerves (fig. 4, o) form, on each side, a 

 strong stem going straight out, which, after having 

 entered the eye-stalks swells out to a club-sha])ed 

 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. 

 Eadi of these is isolated by a cylindrical sheatli 

 (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) surroimding 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 PI. VI, rigs. 3 and 4, PI. 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 fomid in the 

 posterior part of the body, as is the case in the 

 genus Uranchipus. At some distance from their 

 posterior ends, a short, tliick 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 develojiment (see PI. 

 VIII, fig. 11), with a greenish ydlk-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 marsiipium, where it is en- 

 veloped in its shell. This is tolerably firm and 

 thick, and in transverse sections shows a distinct 

 double (lutline. 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. 



