98 



Udspi-inget for Nerveme til Iste Par Folere, nemlig 

 en meget t^Tid Nerve for de i Basaldelen af disse 

 Folere indtrædende Muskier, og en betydelig stærkere 

 Nervestamme, der jiasserer ind i den koUeformige 

 Endedel og til enhver af de laterale Lapjie ndsen- 

 der talrige Fibrer (se Tab. XV, Fig. 5\ Nerveme 

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

 gangliet selv, men fra de fra samme bagtil ndgaaende 

 stærke Commi.ssurer, der omgiver Spiseroret for at 

 forbinde sig medBuggangliekjæden. Man kan t\^de- 

 ligt adskille 2 saadanne Nerver af omtrent ens 

 Tykkelse og ndspringende tæt sammen, noget foran 

 Midten af Commissurerne, som jiaa dette Sted viser 

 en ganske svag ganglios Opsviilmning. Angaaende 

 disse Nervers videre Forlob iml i selve Folerne, har 

 det dog ikke været mig muligt at skaffe mig noget 

 tilfredsstillende Begreb. 



Den ovrige Del af Centralnervesystemet er 

 meget vanskelig at observere og lader sig neppe 

 hverken ved Dissection eller ved andre Metboder 

 fremstille i sin Helhed. Jeg har imidlertid stykke- 

 vis knnnet noiere nndersoge samme og fundet, at 

 den, som hos Branchipodiderne, dannes af 2 vidt 

 adskilte stærke Nervestammer, der passerer bagtil 

 langs Bugsiden af Trnncns og i hvert Segment er 

 forbundne med 2 tynde Tværcommissurer. Nerve- 

 stammerne viser paa dette Sted en gan.ske svag 

 ganglios Opsvulmning og udsender \idad, i adskillig 

 Afstand fra hinanden, 2 stærke Nerver, hvoraf den 

 ene træder ind i den respective Fod, medens den 

 anden synes at i;dbrede sig i Kropjiens Side- 

 mnsknlatnr. 



Forplantningsapparat. — Da alle hidtil obser- 

 verede Exemplarer af denne Phyllopode har vist sig 

 at væi-e af Hunkjon, har vi her kun at omtale 

 Hunorganerne eller Ovarierne. Disse (se Tab. XV, 

 Fig. 1) har Formen af 2 noget .skrueformigt dreiede 

 Ror, der strækker sig igjennem Storsteparten af 

 Truncus, til hver Side af Tarmen, og ender bagtil 

 med en smalere sjndst ndlobende Del. Bagenfor 

 Midten ndgaar fra hvert Ovarium nedad en kort 

 Ægleder, der udmunder i Basis af den tilsvarende 

 Fod af Ilte Par. Fra Overfladen af Ovarialrorene 

 ndgaar talrige smaa Ijlindsækformige ITdvidninger, 

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

 viser et temmelig uniformt Udseende, medens de hos 

 ældre Individer antager en meget forskjellig Fdvik- 

 ling og delvis grupperer sig paa en drueklaseformig 

 Maade (se Fig. 16, 17). Disse Udvidninger er Æg- 

 folliklerne. hvori Æggenes første Dannelse foregaar. 

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

 man i deres Indre altid tinde, som hos Lepidurns, 

 4 Celler combinerede, hvoraf blot den ^^derste bliver 

 til det virkelige Æg, medens de 3 ovrige forestiller 

 Næringsceller. Paa de mindste Follikler, der er 

 nogenlunde cylindriske af Form, er alene de 4 Celle- 



fig. 10), hut are of a similar conical shape. From 

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

 tennæ, viz., a very fine 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 

 latei'al 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 backwards from it. which surround 

 the O'sophagus in order to join the ventral ganglion 

 chain. Two such nerves can be clearly distinguished, 

 of about equal thickness, and issuing close together 

 a little in front of the middle of the commissures 

 which here exhibit a very slight ganglionic swelling. 

 As regards the further course of the nerves in the 

 antennæ tliemselves, it has not been possible for 

 nie to obtain any vei\y satisfactory idea. 



The 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 considerable distance from one another, 2 strong 

 nerves, one of which enters the corresponding leg, 

 while the other seems to spread over the lateral 



musculature of tlie 

 Sexual Organs. 



idv. 



— As all the specimens of this 

 Phyllopod hitherto oljserved have jiroved 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 eacli 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 ovar\', 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 3'oung speci- 

 mens (see PI. 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 expansions are the egg-follicles, in which 

 the eax'liest 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 

 represent alimentary cells. In tlie smallest follicles, 



