THE MEDUSA. 19 



general,) it will not be uninteresting to trace the history 

 of those researches which have thrown light upon this 

 obscure department, in the account of the development 

 of the lower animals. As already observed, we have, in 

 this respect — ^to thank chiefly, the Norwegian naturalist 

 M. Sars, In a short work ' Beyträge zur Naturge- 

 schichte der Seethiere,' (Bergen, 1828,) this observer 

 described two remarkable animals, Scyplnstoma, a polype 

 with a four-sided extensible mouth, and Strobila which 

 resembles a pine cone, and is constituted of a series of 

 ÄcalepU(2 or Medusa, placed one within the other. In 

 his later celebrated work, ' Besclu-eibung und Beobacht- 

 ungen einiger merkwürdigen oder neuen im Meere an der 

 bergenschen küste lebenden Thiere,' (Bergen, 1835,) he 

 States, that the Scyphistoma is not a distinct animal, but 

 the younger state of the animal, which he had formerly 

 named Strobila, and communicates particular observa- 

 tions on this subject, especially with regard to its growth, 

 and the development of the acalepha-like creature. He 

 gives also a description and figure of some free marine 

 animalculse, which must be referred to the genus Epliyra 

 (Eschr.), and which he looked upon as the adult state of 

 S.robila. These observations contained a paradox, which 

 could scarcely be believed, yet no one ventured to deny 

 their truth ; they were unparalleled as it would appear in 

 the course of nature, as known at that time. Ehrenberg, 

 in his well-known work ' Acalephen des rothen Meeres,' 

 explained the Strobila to be a Lucernaria, on the point of 

 undergoing transverse division. 



M. Sars continued his observations on these remark- 

 able forms, but from want of time, his researches met 

 with no attention at the meeting of naturalists at Prague, 

 on which account he published a series of prehminary 

 notices in ' Wiegman's Archiv f. Naturg,' (1837, iii 

 Jahrg., s. 436,) in which he stated, that having pursued 

 the. further development of the Strobila, he had discovered 

 that the free, acalephoid animalculse, were metamorphosed 

 into the commonest of our medusae {Medusa aurita,) and 



