den. Æggene (Fig. 20), som udvikle sig i Væggene af 

 Manubrium, ere kun faa i Antal, men forholdsvis meget 

 store samt af en bleg rosenrødlig gjennemsigtig Farve* 

 De første Anlæg til Æg (Fig. 10—12 og Fig. 13—16) 

 vise sig paa en meget mærkværdig Maade skivedannede 

 eller fladt udbredte, med Peripherien udgaaende i mere 

 eller mindre talrige Udløbere eller Lappe, der ofte ere 

 tvedelte, altsaa af en uregelmæssig Form, lignende mange 

 Amoeber, med en lysere kugledannet Kjærne (Kimblæren) 

 i Centrum eller noget nærmere den ene Side. Senere, 

 som det synes, trække de sig mere sammen (Fig. 16—18), 

 idet de blive tykkere og Lapp ene færre, kortere og bre- 

 dere, og ende med at antage en kuglerund Form (Fig. 

 20), i hvis Indre Kjærnen eller Kimblæren ikke længere 

 er synlig, og rage da høit frem over Manubriums Over- 

 flade ligesom Bær (se Fig. 11), formodentlig fæstede ved 

 en kort Stilk, som i et Tilfælde bemærkedes hos et løs- 

 revet Æg (Fig. 19). Denne Contraction af Protoplasmaet 

 (som man maa antage er Æggets Indhold) maa finde 

 Sted meget langsomt, da den ikke af Øiet kunde bemærkes. 



Æggene af C. Sarsii ere saaledes Celler uden Celle- 

 membran eller blotte nøgne, homogene Plasmaklumper 

 eller Skiver, der hver indslutter en kugledannet Kjærne. 

 De ere i denne Tilstand extensible og contractile ; thi 

 kun ved at antage en saadan Contractilitet (som vistnok 

 endnu ikke directe er observeret) blive de mangfoldige 

 Formforandringer, som de vise, forstaaelige. Analoge 

 Formforandringer eller amoebeagtige Bevægelser har man, 

 som bekjendt, iagttaget hos visse dyriske Celler, nemlig 

 Lymphelegemerne i Blodet, enkelte Bindevævsceller, Hjer- 

 tecellerne af Embryoner o. a. Bevægelser af Blommen 

 iagttoges i Ægget af Gasterosteus (Ransom) og Gjedden 

 (Reichert), i Furingskugler af Frøen (Ecker), i Cellerne 

 af Planarieembryonet (v. Siebold ogKölliker); og Bischoff 

 saa Rotationer af den hele Blommemasse i Kanin- og Mar- 

 svinægget. Endelig bemærker Kölliker (Icones histiologiæ, 

 lste Afd., pag. 50, Tab. 8, Fig. 3) om nogle Spongier: 

 „meget eiendommelige ere de hos Dunstervillia, Nardoa 

 og Ancorina sete flerfoldige Udløbere af Æggene, der give 

 dem Udseende af multipolare Ganglieceller, og maaske 

 hænge sammen med Æggenes Bevægelsesphænomener i 

 levende Live". Denne sidste Iagttagelse af Kölliker er 

 den eneste, jeg har kunnet finde, der synes at staa i nogen- 

 lunde Samklang med det ovenbeskrevne iagttagne mærk- 

 værdige Forhold ved Æggets Udvikling hos C. Sarsii. 

 Köllikers Figurer vise imidlertid tynde, tilspidsede, simple 

 eller 1 — 2 Gange dichstomisk delte Udløbere. Hos Cory- 

 morpha ere disse af en bredere, i Enden tilrundet og 

 mangfoldigen og mere uregelmæssig Form. — Efter nogen 

 Tid drage de amoebeagtige Forlængelser af Blommen hos 

 C. Sarsii sig ind, Blommen bliver tykkere eller concen- 

 trerer sig alt mere og mere og bliver omsider kuglefor- 

 mig og dens Overflade glat; samtidig begynder den at 

 hæve sig frem over Manubriums Overflade ligesom et Bær, 



very most, only to (never beyond) this aperture. The 

 ova (fig. 20) which develop themselves in the walls of the 

 manubrium are only few in number, but proportionally 

 very large and of a pale transparent rose color. The 

 first indications of the ova (fig. 10—12, o, fig. 13 — 16) 

 shew themselves in a very remarkable manner as thin discs 

 with a periphery bordered by more or less numerous 

 processes or lobes which are frequently divided, being 

 thus irregular in form and resembling many Amoebæ, 

 with a lighter globular nucleus (the germinal vesicle) in 

 the centre, or somewhat more on one side. It appears 

 that they afterwards contract themselves more (fig. 16 — 18) 

 becoming thicker, with fewer shorter and wider lobes, 

 and finally assuming a globular form (fig. 20) wherein the 

 interior nucleus or germinal vesicle is no longer visible; 

 in this state they project far above the surface of the 

 manubrium like berries (see fig. 11) probably attached 

 by a short stem which in one case was remarked on a 

 detached ovum (fig. 19). This contraction of the proto- 

 plasma (as which the contents of the ovum may be re- 

 garded) must take place very slowly; for it was not ob- 

 servable to the eye. 



The ova of C. Sarsii are therefore cells without any 

 cellular membrane, or merely naked homogeneous plas- 

 matic masses, or discs, each of which contains a globu- 

 lar nucleus. They are in this state extensile and con- 

 tractile; for it is only by assuming the existence of such 

 contractility (which has certainly not yet been directly 

 observed) that it becomes possible to account for the 

 manifold mutations of form which they exhibit. Analog- 

 ous mutations or Amoeba-like movements have been ob- 

 served, as is well known, in certain animal cells, namely 

 in the lymph-globules of the blood, in some connecting- 

 tissue-cells, in the cells of the heart in embryos &c. 

 Movements of the yolk have been observed in the ova 

 of the Gasterosteus (Ransom) and of the Pike (Reichert), 

 in segmentation-globules of the spawn of the Frog (Ecker), 

 in the cells of the embryos of Planaria (v. Siebold & 

 Kölliker) ; Bischoff noticed rotations of the whole mass of 

 the yolk in the ovum of the rabbit and guinea-pig; and 

 lastly Kölliker remarks (Icones histiologiæ, Part 1, p. 50, 

 Tab. 8, fig. 3) concerning some sponges: "The multifari- 

 ous off-shoots observed on the ova of Dunstervillia Nar- 

 doa and Ancorina are very peculiar, and give them the 

 appearance of multipolar ganglion-cells; possibly they may 

 also stand in connexion with the phenomena of movement 

 in the eggs during life." The last observation of Kölliker 

 is the only one I have been able to find that appears in 

 any way to coincide with the remarkable development of 

 the egg in C. Sarsii as above described. Kölliker's figures 

 shew however thin, pointed, simple or once or twice 

 dichotomically divided processes. In the Corymorpha 

 these are wider, more rounded at the extremity, more 

 various and of more irregular shape. After some time 

 the Amoeba-like elongations of the yolk in the C. Sarsii 

 retract themselves, the yolk becomes denser and more 



