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70 CLASS II. 
arms, when separated, grew into new Polyps; an experiment which 
did not succeed with Tremptey. The power of reproduction is 
in Actiniw just as great; they regenerate parts that have been cut 
away, and admit of propagation by artificial division, as DicQUEMARE 
especially has shewn by his experiments. 
Before leaving the propagation of Polyps, we must notice those 
late observations which indicate so close an affinity between Medusce 
and certain Polyps, that in time probably a great revolution will 
be made in the systematic arrangement of the animal kingdom. 
In Syncoryne, for instance, and Coryne (Clava), and certain Cam- 
panularie bell-shaped appendages or off-shoots have been noticed, 
which at length are separated from the stem, and resemble minute 
Meduse. Conversely, also, the observations of Sars and of Von 
Srepotp have shewn that Meduse come from the egg under an 
oblong form resembling that of infusories beset with cilia: these 
move freely, at first, then fix themselves, lose their cilia, become 
clavate, acquire arms, and perfectly resemble Hydra. These hydra- 
like forms divide by transverse indentations, and separate into rings 
from which Medusw arise. 
. It is possible, therefore, that all hydra-form Polyps may be only 
imperfect forms of Meduse. And if so, those animals which 
R#AUMUR first named Polyps, would no longer belong to this class. 
But on this supposition it is wonderful that Spermatozoa should be 
observed in Hydra and Coryne: a fact that may cause us to hesitate . 
before we conclude, with DusArpiy, that the eggs, described above 
(p. 68), are Bulbilli. At all events the perfect form of Hydra would 
then be unknown!. 
1 We cannot detail these observations more particularly, without being diffuse 
beyond our object. Let it suffice to refer the reader to Lovin Stockh. Vetensk, Akad, 
Handl. 1836 ; Winemann’s Archiv fiir Naturgesch. Vv. 1837, 8. 219 —262, 8. 321—326; 
Ann. des Sc. nat. sec. Série. Tom. xv. Zool. pp. 157—176. (Observations sur le 
dévéloppement et les metamorphoses des genres Campanulaire et Syncoryne.) 
Sars, Beskrievelser og Jagttagelser over nogle maerkelige eller nije + Havet ved der 
Bergenske Kyst levende Dyr. Bergen, 1835. 
C. Tu. V. Sresonp, Neueste Schriften der naturf. Gesellsch. in Danzig 11. 2 Heft 
1839, 8s. 26—35. 
Sars, Mém. sur le dévéloppement de la Medusa aurita et de la Cyanea capillata. 
Ann. des Sc. nat. sec. Série. Tom, xvi. Zoologie, pp. 321—348. 
STEENSTRUP om Fortplantning og Udvikling gjennem vexlende Generationsraekker. 
Kjobenhavn, 1842. 40. (Translated by G. Busk for the Ray Soc. from the German 
Translat. 1845, On the Alternation of Generations.) 
