(mit Ausschluss der Siphouophora) für 1904. 43 



sea, obtained by evaporation; 2. by dissolving in distilled water chemi- 

 cally prepared salts in proportions determined by analysis. The 

 Challenger analysis by Dittmar were used. Zur Kontrolle der damit 

 beschickten Aquarien dienten Aquarien mit Seewasser aus "Woods 

 Hole. Two sets of such aquaria were prepared: (1) Standing 

 aquaria kept at constant salt content by the addition of fresh 

 water; 2. a aquaria through which a small stream of water 

 was kept flowing, providing thereby a System of closed circu- 

 lation. Beide Aquarien wurden mit Pflanzen und Thieren besetzt. 

 Gonionemus survived for several weeks in both Solutions, but appeared 

 to suffer from other forms of life with which it came in contact .... 

 Several other forms of fish and invertebrates were tested in various 

 ways, with the general result that the artificial Solution made from the 

 salt obtained by evaporation permitted survival to a degree not clearly 

 different from that seen in sea water. The synthetic artificial Solution 

 seemed equally favorable to most forms, but distinctly less so to a few. 



Perkins (nach Sumiier p. 250, L) hat in Woods Hole vom 6. Juli 

 bis 4. August fast jeden Tag reife Gonionemus gefangen, and the eggs 

 obtained from these were reared in a variety of ways with a view to 

 having the larvae mature in the laboratory. Many thousand polyps 

 are now under Observation . . Es wurden Beobachtungen über die 

 Degeneration der Tentakeln gemacht. Andre Experimente sollen 

 feststellen, wie weit es möglich wäre, unter künstlichen Bedingungen 

 Medusenlarven zu züchten. t'Iias. W. Ilargitt (4) hat die Eudendrium 

 Planula in Woods Hole und Neapel gezüchtet. Gleich nach dem 

 Ausschlüpfen ist sie heliotropisch; sie schlüpft bei Polypen, die früh 

 ins Laboratorium gebracht wurden, chiefly during early midday aus. 

 Der Heliotropismus rapidly declines, however, during later life, tho 

 still persists even in the hydroids themselves as numerous experiments 

 by Loeb and other have shown. Manche Planulae gabelten sich, und 

 meist am oralen Ende, Pennaria-Planulae neigten noch mehr dazu. 

 The fixation of the planula and development of the hydranth usually 

 occurs within two or three days, tho it is sometimes, in specimens 

 reared in small aquaria, consiclerably defered. Fixirung by a slimy 

 secretion, und Bildung eines zarten Perisarks. Dann Ruhe und endlich 

 Ausbildung der Polypen. 



Aurelia und Cyanea von New England waters halten sich nach 

 Chas. W. Hargitt (5) p. 74 nicht so gut im Aquarium wie Rhizostoma 

 pulmo, die sich unverletzt oder nach Verstümmelung noch wochen- 

 lang beobachten lässt. 



Konservirung: I.Eier, Spermien, Planulae. 

 Pennaria tiarella McCr. Chas. W. Hargitt (4) p. 454 — 455: Kleinen- 

 bergs Gemische sind most worthless zum Studium früher Entwick- 

 lungsstadien the various corrosive Sublimate Solutions ergaben the 

 best results, besonders die alkoholischen Lösungen. Zusatz von 

 Essigsäure erwies sich ohne Werth. Flemings und Hermanns Ge- 

 mische ergaben ausgezeichnete Fixirungen, but rendered subsequent 

 staining difficult and more or less unsatisfactory. Auch Formol 



