39 



Mm. lange og 1 T | 2 Mm. tykke over Midten, contraherede 

 5—6 Mm. lange og 2—3 Mm. tykke, altsaa forholdsvis 

 større end hos P. hydrostatica. Deres Endestykke eller 

 Snabelen (Fig. 24, s) viste rundtom 12 regelmæssige opake 

 Længdestriber eller Folder. 



FANGTRAADENE. 

 Fangtraadene (tentacula), som paa mit største Exem- 

 plar fattedes, vare paa det mindste overalt tilstede, en 

 for hvert Sugerør, fæstet ved dets Basis umiddelbart over 

 dens Tilheftningspunkt, med Undtagelse af de 2 yngste 

 eller nærmest Vegetationspunktet siddende Sugerør, hvor 

 den endnu ikke var udviklet. Fangtraaden (Fig. 23, 24 t) 

 var i stærkt contraheret Tilstand (i Spiritus), i hvilken den 

 var oprullet i 8—9 vide skrueformige Spiraler, 5—6 Mm. 

 lang og lidt mere end 1 | 2 Mm. tyk; i levende Tilstand og 

 udstrakt har den sikkert, ligesom hos alle Physophorider, 

 været mangfoldige Gange længere og tyndere. Den er 

 cylindrisk, glat, men ved Contraction tæt ringet, og langs 

 den ene Side besat med en Rad af overmaade tynde se- 

 cundære Traade, hvilke ende i en saakaldet Nessélhnop; 

 denne fattes dog paa de inderste eller nærmest ved Basis 

 af Fangtraaden siddende, mindre udviklede Sidetraade. 

 Man kan nemlig her forfølge Nesselknoppens gradvise Ud- 

 vikling. Først (d. e. inderst ved Fangtraadens Basis, hvor 

 deres Vegetationspunkt er) ere Sidetraadene meget korte 

 og ligesom smaa simple Blindtarme (Fig. 25, 26), hvilke 

 efterhaanden forlænges og afdele sig i en inderste Del 

 (Stilken, Fig. 27 — 29, a), en midterste tykkere Del (Nes- 

 selknoppen, sacculus, Huxley, ibid. b) og en yderste Del 

 (Endetraaden, filamentum, Huxley, ibid. c). En gjennem- 

 sigtig Hud, Begyndelsen til den senere Kapsel eller Kappe 

 (involucrum, Huxley) danner sig imidlertid om den fortyk- 

 kede Del af Strengen eller Nesselknoppen, som efterhaan- 

 den begynder at vise Tegn til Spiraldreining ved 1 eller 2 

 langt udtrukne Skruevendinger (Fig. 28, 29). Nu optræde 

 Nesselceller, navnlig de store elliptiske saakaldte „gule 

 Celler", i et ringe Antal og uden synlig regelmæssig An- 

 ordning i den inderste Del af Skruen. Senere lægge Skrue- 

 vendingerne, som forøges til 4 eller 5 (hos P, hydrostatica 

 derimod, efter Keferstein og Ehlers, til omtrent 8), sig tæt 

 sammen til hinanden (Fig. 29, 30), idet Kapselen bliver 

 bredere eller oval og Endetraaden efterhaanden drages 

 ind i den, saa at omsider kun en liden to- eller trelappet 

 Del af den (Fig. 31, 31', c) rager frem ud af en liden paa 

 Kapselens Ende værende Aabning. — Hos de mest udvik- 

 lede af mig iagttagne Nesselknopper (Fig. 32, 33), var den 

 omhyllende Kapsel mere langstrakt eller elliptisk med 

 smalere but tilrundet ydre Ende. Imidlertid er der fore- 

 gaaet en Omdreining af den nu fuldkommen af Kapselen 

 omsluttede og 5 Spiraldreininger dannende (intensiv pur- 

 purrøde) Streng (det saakaldte Nesselbaand) saaledes, at 

 de store gule Nesselceller, som før laa nærmest ved Kap- 

 selens Basis, ere komne til at ligge nærmest ved dens 



large as the former, the suction-tubes (fig. 23, aa, fig. 24) 

 were well preserved and of a reddish color; the largest 

 when extended were 10 Mm. long and l 1 /^ Mm. thick 

 across the middle; when contracted 5-6 Mm. long, and 

 2—3 Mm. thick, that is relatively larger than in P. hydro- 

 statica. Around the terminal part or proboscis (fig. 24 s) 

 there appeared 12 regular opaque longitudinal stripes 

 or folds. 



THE TENTACULAR FILAMENTS. 

 The tentacular filaments (tentacula), which were wan- 

 ting in my largest specimen, were all present in the smaller, 

 one for each suction-tube fixed at the base immediately 

 above the attachment of the tube, w ith exception of the 

 two youngest suction-tubes situated nearest to the vegeta- 

 tion-point, in which two the filament was not yet developed. 

 The filament (fig. 23, 24 t) was in a strongly contracted 

 state (in spirit) and coiled up in 8—9 wide screw-like 

 spirals, 5—6 Mm. long, and a little more than ] / 2 . Mm. 

 thick; in the living state and when extended it has certain- 

 ly been, as in all Physophoridæ, many times longer and 

 thinner. It is cylindrical' smooth, but by contraction closely 

 ringed, and along one side covered with a row of extreme- 

 ly thin secondary filaments which terminate in a so-called 

 urticary Jcnob; this is however wanting in the interior less 

 developed lateral filaments situated nearest to the base of 

 the tentacle. The gradual development of the urticary 

 knobs can here be followed. First (i. e. innermost near 

 the base of the tentacle where its vegetation-point is) 

 the lateral threads are very short, and like small simple 

 caeca (üg. 25, 26) which gradually become longer and di- 

 vide themselves into an interior part (the stem fig. 27— 29 a) 

 a central thicker part (the urticary bud, sacculus Huxley 

 ibid b) and an exterior part (the terminal thread, filamen- 

 tum Huxley ibid c.) A transparent skin, the commence- 

 ment of the future capsule or mantle (involucrum Huxley) 

 forms itself round the thickened part of the chord or the 

 urticary knob, which gradually begins to shew signs of 

 spiral twisting in 1 or 2 long drawn screw turns (fig. 28 

 29), Now the thread-cells begin to appear, especially the 

 large elliptical so-called " yellow cells", in small number 

 and without any apparent regular arrangement in the in- 

 terior part of the screw. Subsequently the coils of the 

 screw, which are increased up to 4 — 5 in number (but in 

 the P. hydrostatica according to Keferstein and Ehlers to 

 about 8) lay themselves closely together (fig. 29, 30) while 

 the capsule becomes wider or oval, and the terminal fila- 

 ment is gradually drawn into it, so that at last there is 

 only a small two- or three-lobed part of it (üg. 31, 31'c) 

 projecting from a small aperture at the extremity of the 

 capsule. In the most developed urticary knobs observed 

 by me (fig. 32, 33) the enveloping capsule was more elon- 

 gated or elliptical with a thinner obtusely rounded outer 

 extremity. In the mean time there has occurred a revolu- 

 tion of the (intense purple-red) chord (the so-called urti- 

 cary band) — which is now completely enveloped by the 

 capsule and forms 5 spiral coils — so that the large yellow 



MMHM 



