113 



ganske stopper op. Det sker kun, naar D\-ret phid- 

 selig foruroliges, i hvilket Tiltælile alle Dele af 

 Legemet lini-tigt trækkes incl i Skallen. In-orpaa 

 denne liermetisk lukker sig og Dyret synker til- 

 linnds. Meget snart aabner imidlertid Valvlerne 

 sig igjen, den forreste Del af Hovedet tilligemed 

 Aarerne strækker sig forsigtigt frem fortil. og Halen 

 liagtil, hvorpaa igjen Branchialfodderne hegynder 

 sine rli\tlinnske svingende Bevægelser. 



Dyi'et synes liovedsageligt at nære sig af op- 

 smuldrede Plantedele, encellede Alger, maaske ogsaa 

 Infusorier. Disse Dele bliver ved Brancliialfoddernos 

 Bevægelser livirvlet ind i Skallen og ])asserei- der- 

 efter bagfra fortil mellem Fodderne imod Munden. 

 Kindljakkerne sees at være i stadig Aktivitet med 

 at bearbeide den af Mnnden (i])tagne Næring, som 

 derefter ved Hjælp af de talrige fra Overlæben til 

 Sjuseroret gaaende Musklers \'irkning bliver svælgt 

 og indfort i Tarmens forreste Del. Her undergaar 

 Foden en forelobig U]>losningsproces ved det intenst 

 gule Secret, der udsondres af Leveren. Fordoiel.sen 

 synes idethele at gaa meget hurtigt for sig, idet 

 Tarmens Contenta hurtigt forandrer sin Farve, efter- 

 som de passerer bag-til, fra lyst gult eller orange 

 til et meget morkt brunt eller næsten sort. Med 

 visse Mellemrum bliver Excrementerne ved Ende- 

 tarmens Contractioner udstodte, ofte i temmelig lange 

 sammenhængende Masser. I Lighed med hvad Til- 

 fældet er hos Branchipodiderne, observeres ofte i 

 Tarmrorets Vægge energiske ])eristaltiske Bevæ- 

 gelser. 



Som ovenfor anfort, har alle liidtil observerede 

 Individer af denne Form vist sig, ifolge sit hele 

 Fdseende, at være Hunner, og alle Exemplarer l)li- 

 ver ogsaa uden Undtagel.se, naar de har opnaaet en 

 visCIrad a f Udvikling, forsyuede med de characteri- 

 stiske Ægpaketter under Skallens dorsale Del. Da 

 jeg liar observeret denne Form gjennem en Række 

 af Aar til forskjellige Tider af Sonnneren, og tillige 

 gjentagne Gange har opdrættet den i mine Aqvarier 

 og havt den gaaende lier niaanedsvis, trcu- jeg med 

 fnld Sikkerhed at kunne constatere, at Hanner over- 

 hovedet ikke existerer, og at altsaa nærværende 

 IMiyllopodes Forplantning er exclusiv parthenogene- 

 tisk. Dette er saamegct mere nucrkcligt som For- 

 juddet er et helt andet med Arterne af den meget 

 nærstaaende Slægt Eulimadia, hvor Forplantningen 

 er udpræget bisexuel (dier ganujgenetisk, idet Han- 

 ner og Hunner til alle Tider synes at forekomme i 

 omtrent lige Antal. En Tid har jeg rigtignok staaet 

 i den Formening, at alle Indi\ider af den her om- 

 handlede rhyllopode maaske kunde være hermaphro- 

 ditiske eller rettere protandriske, idet visse Forhold 

 ved Kjonsorganernes Bygning syntes mig at pege 

 i denne Retning; men Kesultaterne af de af mig 



15 — G. 0. Sara: Fauna Korvegiif. 



gracious, uiululatoi-y motion. It is, on the wlmle. 

 very seldom that this swinging motion of the 

 branchial legs entirely ceases; for it ha])])ens only 

 when the animal is suddenly alarmed, in which case 

 all the parts of the body are withdrawn into the 

 shell, whi(di then closes hermetically, and the animal 

 .sinks to the bottom. The valves, however, very soon 

 reopen, and the fore jiart of the head, together with 

 the oars, is cautiously extended in front, and the 

 tail behind, whereupon the branchial legs recom- 

 mence their rhythmical swinging movements. 



The animal a])pears to feed principally on 

 broken portions of plants, unicellular alga», and 

 possibly infusoria. Tliese are whirled into the shell 

 l)y the movements of the 1)rancliial legs, and then 

 pass from back to front Ijetween the legs towai'ds 

 the mouth. The mandibles are seen to be con- 

 stantly occupied in mani]iulating the food taken in 

 by the mouth, which then, by the aid of the nu- 

 merous muscles running from the labrum to the 

 æsophagus, is swallowed and introduced into the 

 anterior ])art of the intestine. Here the food under- 

 goes a preliminary process of dissolution by the 

 intensely yellow secretion deposited by the liver. 

 Digestion seems on the whole to take place very 

 rapidly, the contents of the intestine ([uickly 

 changing colour as they pass backwards, from light 

 yellow or orange to a very dark brown or almost 

 black. At certain intervals the excrements are 

 ejected by the contractions of the rectum, often in 

 rather long, connected masses. As in the Branchi- 

 podidæ, energetic ])eristaltic movements may often 

 be observed in the walls of the intestinal tube. 



As stated above, all the specimens of this form 

 hitherto observed, have proveil, from their whole 

 appearance, to be females; and all specimens, 

 without exception, when they have attained to a 

 certain degree of development, ai'e provided with 

 the characteristit' (duster of eggs beneath the 

 dorsal part of the shell. Havin» observed this form 

 at difterent ])eriods of the summer through a series 

 of years, and having also reared it repeatedly in 

 my aipiaria, where it has existed tor months toge- 

 ther, 1 think I nuiy ihnlare with perfect certainty 

 that males in reality do not exist, and that the 

 propagation of this I'hylb.jKul is thus exclusively 

 parthenogenetic. This is so miicii the more remark- 

 able, as the circumstance is altogether diti'erent in 

 the species of the very nearly-allied genus J'JiiU- 

 madia, where jirnpagation is very markedly bi-sexual 

 or gamogenetic, nmles and females seeming at all 

 seasons to occur in about ei|ual numbers. At one 

 time indeed, 1 was under the impression tlu\t all 

 the specimens of tiie I'liyllopod in (juestion miglit 

 perhajjs be hermaphroditic, or rather protandric, as 

 certain circumstances in the structure of tiie sexual 

 organs seemed to me to point in that dire(tii>n; 



