ganske stopper op. Det sker kun, naar Dyret plud- 
selig foruroliges, i hvilket Tilfeelde alle Dele af 
Legemet hurtigt trekkes ind i Skallen, hvorpaa 
denne hermetisk lukker sig og Dyret synker til- 
bunds. Meget snart aabner imidlertid Valvlerne 
sig igjen, den forreste Del af Hovedet tilligemed 
Aarerne strekker sig forsigtigt frem fortil, og Halen 
bagtil, hvorpaa igjen Branchialfodderne begynder 
sine rhythmiske svingende Beveegelser. 
Dyret synes hovedsageligt at nere sig af op- 
smuldrede Plantedele, encellede Alger, maaske ogsaa 
Infusorier. Disse Dele bliver ved Branchialfoddernes 
Bevegelser hvirvlet ind i Skallen og passerer der- 
efter bagfra fortil mellem Fodderne imod Munden. 
Kindbakkerne sees at vere i stadig Aktivitet med 
at bearbeide den af Munden optagne Nering, som 
derefter ved Hjelp af de talrige fra Overleben til 
Spiseroret gaaende Musklers Virkning bliver svelgt 
og indfort i Tarmens forreste Del. Her undergaar 
Foden en forelobig Oplosningsproces ved det intenst 
gule Secret, der udsondres af Leveren. Fordgielsen 
synes idethele at gaa meget hurtigt for sig, idet 
Tarmens Contenta hurtigt forandrer sin Farve, efter- 
som de passerer bagtil, fra lyst gult eller orange 
til et meget morkt brunt eller nesten sort. Med 
visse Mellemrum bliver Excrementerne ved Ende- 
tarmens Contractioner udstedte, ofte’i temmelig lange 
sammenheengende Masser. I Lighed med hvad Til- 
feeldet er hos Branchipodiderne, observeres ofte i 
Tarmrorets Vegge energiske peristaltiske Beve- 
gelser. 
Som ovenfor anfort, har alle hidtil observerede 
Individer af denne Form vist sig, ifolge sit hele 
Udseende, at vere Hunner, og alle Exemplarer bli- 
ver ogsaa uden Undtagelse, naar de har opnaaet en 
vis Grad af Udvikling, forsynede med de characteri- 
stiske AZgpaketter under Skallens dorsale Del. Da 
jeg har observeret denne Form gjennem en Rekke 
af Aar til forskjellige Tider af Sommeren, og tillige 
gjentagne Gange har opdrettet den i mine Aqvarier 
og havt den gaaende her maanedsvis, tror jeg med 
fuld Sikkerhed at kunne constatere, at Hanner over- | 
hovedet ikke existerer, og at altsaa nerveerende 
Phyllopodes Forplantning er exclusiv parthenogene- 
tisk. Dette er saameget mere merkeligt som For- 
holdet er et helt andet med Arterne af den meget 
neerstaaende Slegt Eulimadia; hvor Forplantningen 
er udpreeget bisexuel eller gamogenetisk, 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 Individer af den her om- 
handlede Phyllopode maaske kunde vere hermaphro- 
ditiske eller rettere protandriske, idet visse Forhold 
ved Kjonsorganernes Bygning syntes mig at pege 
i denne Retning; men Resultaterne af de af mig 
15 — G. 0, Sars: Fauna Norvegiz. 
113 
parthenogenetic. 
gracious, undulatory motion. It is, on the whole, 
very seldom that this swinging motion of the 
branchial legs entirely ceases; for it happens only 
when the animal is suddenly alarmed, in which case 
all the parts of the body are withdrawn into the 
shell, which then closes hermetically, and the animal 
sinks to the bottom. The valves, however, very soon 
reopen, and the fore part 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 appears to feed principally on 
broken portions of plants, unicellular alge, and 
possibly infusoria. These are whirled into the shell 
by the movements of the branchial legs, and then 
pass from back to front between the legs towards 
the mouth. The mandibles are seen to be con- 
stantly oceupied in manipulating the food taken in 
by the mouth, which then, by the aid of the nu 
merous muscles running from the labrum to the 
jesophagus, is swallowed and introduced into the 
anterior part 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 quickly 
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- 
podide, energetic peristaltic movements may often 
be observed in the walls of the intestinal tube. 
As. stated above, all the specimens of this form 
hitherto observed, have proved, from their whole 
appearance, to be females; and all specimens, 
without exception, when they have attained to a 
certain degree of development, are provided with 
the characteristic cluster of eggs beneath the 
dorsal part of the shell. Having observed this form 
at different periods of the summer through a series 
of years, and haying also reared it repeatedly in 
my aquaria, where it has existed for months toge- 
ther, I think I may declare with perfect certainty 
that. males in reality do not exist, and that the 
propagation of this Phyllopod is thus exclusively 
This is.so much the more remark- 
able, as the circumstance is altogether different in 
the species of the very nearly-allied genus Euli- 
madia, where propagation is very markedly bi-sexual 
or gamogenetic, males and females seeming at all 
seasons to occur in about equal numbers. At one 
time indeed, I was under the impression that all 
the specimens of the Phyllopod in question might 
perhaps be hermaphroditic, or rather protandric, as 
certain circumstances in the structure of the sexual 
organs seemed to me to point in. that direction; 
