88 M. Sars on an Intestinal Worm in an Acaleph. 



more abundant would be detected. And if the naturalist be al- 

 lowed to assume, that in the existing creation, " within and be- 

 neath all that minuteness which the aided eye of man is able to 

 explore, there may be a world of invisible beings ; and that could 

 we draw aside the mysterious curtain which shrouds them from 

 our senses, we should behold a theatre of as many wonders as 

 astronomy can unfold, — a universe within the compass of a point 

 so small as to elude all the powers of the microscope,^^ — surely 

 the geologist may be permitted to conclude, that a large propor- 

 tion of the sedimentary strata, which at present appears to con- 

 sist of amorphous particles of lime, of flint, and of iron, may be 

 the aggregated skeletons of beings yet more infinitesimal than 

 those which have formed the subject of the present communica- 

 tion. 



19 Chester Square, Pimlico, May 1845. 



VIII. — On the Occurrence of an Intestinal Worm in an Acaleph, 

 By M. Sars*. 



[With a Plate.] 



In Wiegmann^s Archiv,' vol. ii. p. 322, 1841 (Annals, vol. iii. 

 p. 148), it is stated that a parasitical worm resembling a Filaria 

 had been discovered by Prof. E. Forbes in a species of Cydippe, 

 and subsequently (vol. ii. p. 370, 1842), that this parasite, which 

 attaches itself by means of four suckers to the walls of the stomach 

 or vessels, had been described by Messrs. Forbes and Goodsir 

 under the name of Tetrastoma Playfairii. The reporter adds, that 

 further observation would be of interest, as hitherto no intestinal 

 worms had been met with in the Medusa. 



The reporter had forgotten that the discovery of an intestinal 

 worm in an Acaleph had been published by me already in the 

 year 1837. (See Ann. des Sci. Nat. 1837, vol. vii. p. 247.) 



It is not to claim any priority as to this discovery, which is a 

 matter of perfect indifference to science, that I return to this 

 subject, but merely to communicate the following short notices 

 written down in 1835, which 1 have hitherto kept back on ac- 

 count of their imperfect state, in the hope, unfortunately hitherto 

 delusive, of completing them by further observations. 



It was on a gigantic individual of my Mnemia norwegica, five 

 inches in length, which I caught on the 4th of November 1835, 

 near the island Floroe,that I observed, within the transparent clear 

 body, from ten to twelve longish opake white bodies of about a 

 line in length, which proved, on closer examination, to be intes- 



• Translated from Wiegmann's Archiv, 1845, part 1. 



