98 



Udspringet for Nerverne til Iste Par Folere, nemlig 

 en meget tynd Nerve for de i Basaldelen af disse 

 Følere indtrædende Muskler, og en betydelig stærkere 

 Nervestamme, der passerer ind i den kolleformige 

 Endedel og til enhver af de laterale Lappe tidsen- 

 der talrige Fibrer (se Tab. XV, Fig. 5). Nerverne 

 for 2det Par Folere (a''') iidgaar ikke fra Hjerne- 

 gangliet selv, men fra de fra samme bagtil udgaaende 

 stærke Commissurer, der omgiver Spiserøret for at 

 forlunde sig med Buggangliekjæden. Man kan tyde- 

 ligt adskille 2 saadanne Nerver af omtrent ens 

 Tykkelse og ndspringende tæt sammen, noget foran 

 Midten af Commissnrerne, som pa a dette Sted viser 

 en ganske svag ganglies Opsvulmning. Angaaende 

 disse Nervers videre Forlob ind i selve Folerne, har 

 det dog ikke været mig muligt at skaffe mig noget 

 tilfreds.stillende Begreb. 



Den øvrige Del af Centralnervesystemet er 

 meget vanskelig at observere og lader sig neppe 

 hverken ved Dissection ellel- ved andre Methoder 

 fremstille i sin Hellied. Jeg har imidlertid stykke- 

 vis kunnet nøiere undersøge samme og fundet, at 

 den, som hos Branchipodiderne, dannes af 2 vidt 

 adskilte stærke Nervestammer, der passerer Ijagtil 

 langs Bagsiden af Trunciis og i hvert Segment er 

 forbundne med 2 tynde Tværcommissurer. Nerve- 

 stammerne viser paa dette Sted en ganske svag 

 ganglies Opsvulmning og Tidsender udåd, i adskillig 

 Afstand fra hinanden, 2 stærke Nerver, hvoraf den 

 ene træder ind i den respective Fod, medens den 

 anden synes at iidbrede sig i Kroppens Side- 

 niTTskulatur. 



Forplantningsapparat. — Da alle hidtil obser- 

 verede Exenijjlarer af denne Phyllopode har vist sig 

 at være af Hunkjon, har vi her kun at omtale 

 Hunorganerne eller Ovarierne. Disse (se Tab. XV, 

 Fig. 1) har Formen af 2 noget skrueformigt dreiede 

 flor, der strækker sig igjennem Størsteparten af 

 Truncus, til hver Side af Tarmen, og ender bagtil 

 med en smalere spidst udlobende Del " Bagenfor 

 Midten udgaar fra hvert Ovarium nedad en kort 

 Ægleder, der udmunder i Basis af den tilsvarende 

 Fod af Ilte Par. Fra Overtladen af Ovarialrorene 

 udgaar talrige smaa blindsækformige Udvidninger, 

 som hos ganske unge Individer (se Tab. XVI, Fig. 15) 

 viser et temmelig imiformt Udseende, medens de hos 

 ældre Individer antager en meget forskjellig Udvik- 

 ling og delvis grupperer sig paa en drueklaseformig 

 Maade (se Fig. 1(J, 17). Disse Udvidninger er Æg- 

 foUiklerne. hvori Æggenes første Dannelse foregaar. 

 Undersoges disse Follikler noiere (se Fig. 18), vil 

 man i deres Indre altid tinde, som hos Lepidurus, 

 4 Celler combinerede, hvoraf blot den yderste bliver 

 til det virkelige Æg, medens de 3 øvrige forestiller 

 Næringsceller. Paa de mindste Follikler, der er 

 nogenlunde cylindriske af Form, er alene de 4 Celle- 



hg. 10), but are of a similar conical shape. From 

 them originate the nerves før the 1st pair of an- 

 tennæ, viz., a very iine nerve for the muscles in the 

 basal part of these antennæ, and a much stronger 

 nerve-stem which passes into the club-like terminal 

 part, and sends off numerous fibres to each of the 

 lateral lobes (see PI. XV, fig. 5). The nerves for 

 the 2nd pair of antennæ (a^) do not issue from the 

 cerebral ganglion itself, but from the .strong com- 

 missures running l)ack\vards from it, which surround 

 the æsophagus in order to join the ventral ganglion 

 chain. Two such nerves can be clearly distinguished, 

 of about ef[ual thickness, ;nul issuing close togetlier 

 a little in front of the middle of the commissures 

 which here exhibit a very slight ganglionic swelHng. 

 As regards the further course of the nerves in the 

 antennæ themselves, it has not been possible for 

 me to obtain any very satisfactory idea. 



Tiie remainder of the central nervous .system is 

 very difficult to observe, and scarcely allows of 

 being represented in its entirety, either by dissec- 

 tion or by any other method. I have, however, been 

 able to examine parts of it in detail, and have 

 found that, as in the Branchipodidæ, it is formed of 

 2 widely-separated, strong nerve-stems, passing back- 

 wards along the ventral side of the trunk, and 

 connected in each segment with 2 thin transverse 

 commissures. The nerve-stems here exhibit a very 

 slight ganglionic swelling, and send out outwards, 

 at a consideralile distance from one another, 2 strong 

 nerves, one of which enters the corresponding leg, 

 while the other seems to spread over the lateral 

 miTsculature of the body. 



Sexual Organs. — As all the specimens of this 

 Phyllo]xid hitherto observed have proved to be of 

 the female sex, we have here only to describe the 

 female organs or ovaries. These (see PI. XV, fig. 1) 

 are in the shape of 2 tubes, twisted somewhat after 

 the manner of a screw, which extend through the 

 greater part of the trunk on each side of the intes- 

 tine, ending behind in a narrower, pointed part. 

 Beyond the middle, a short oviduct issues in a 

 downward direction from each ovary, opening one 

 on each side at the base of the 11th leg. From the 

 surface of the ovarial tubes, there issue numerous 

 small cæcal expansions, which in quite young speci- 

 mens (see PL XVI, fig. 15) present a fairly uniform 

 appearance, while in older animals they assume a 

 very varied development, and are to a certain 

 extent grouped in a botryoidal manner (see figs. 16, 

 17). These expan.sions are the egg-follicles, in which 

 the earliest formation of the ova takes place. On 

 a close examination of these follicles (see fig. 18) 

 there will always be found inside them, as in Le- 

 pidurus, 4 cells combined, of which only the outer 

 one turns into a true ovum, while the other 3 

 reju'esent alimentary cells. In the smallest follicles. 



