152 METAMORPHOSES OF MAN 



an almost hemispherical umbrella, of from ten to 

 twelve centimetres wide, of a pale red colour, which 

 is due to the vascular ramifications, and provided at 

 its margin with numerous short reddish tentacles. 



The Aurelia deposits ova, which are characterized 

 by the presence of the three concentric spheres to 

 which we alluded in the third chapter of this volume, 

 and these eggs are converted into larvae, which are at 

 first not unlike those of Hermella and Teredo. Their 

 oval body, which is apparently quite homogeneous, 

 is covered with vibratile cilia, and presents a little 

 depression anteriorly. For some time they swim 

 about very actively, just like Infusoria, which they 

 resemble so strongly, that any one confining his 

 observations to this portion of their existence, would 

 certainly be deceived as to their real character. 



This first phase in the life of Medusas extends over 

 a period of about forty-eight hours. The movements 

 then become more feeble, and the young larva seems 

 exhausted, and attaches itself to some solid body, by 

 means of the little depression already mentioned. 

 The animal, which had hitherto been nomadic, hence- 

 forth is fixed and stationary, and a thick mucus, which 



Dumeril discovered, about the end of the last century, were mere 

 excavations in a homogeneous matter, devoid of the characters 

 of a tissue. Oken and his disciples founded part of their doctrines 

 on this statement, which they accepted without examining. Ehren- 

 berg demonstrated that there are tissues, organs, and even complex 

 systems present in the Aurelia. He did in our days, for this group, 

 what Lyonnet did in his for the insect class, and by depriving the 

 " Philosophic de la Nature " of one of its chief foundations, he 

 conferred a signal benefit on Natural Science. Besides, other 

 naturalists, and especially Agassiz, Edwards, Huxley, and Will, 

 have confirmed the general results of the Berlin savant's researches, 

 and I myself have on many occasions perceived their accuracy. 



