518 Notices of Irish Entozoa. 



which have a greater density than fresh water, the change 

 does not take place. Miiller remarks, in describing his Ecli. 

 candidus,* that specimens which had been distended by im- 

 mersion in fresh, and then removed into sea water again, be- 

 came lax and corrugated. I have made a similar experiment 

 frequently, by placing distended specimens in a solution of 

 common salt, of as nearly the strength of sea water as I could 

 determine by its taste, and a similar result followed. The 

 specimens, from being swelled to their utmost extent, from 

 being firm, rigid, smooth, without the slightest appearance 

 of motion or life, and with the proboscis extended, soon be- 

 came flaccid, with the proboscis drawn in, the body shorten- 

 ed to half its previous length, curved, rugose, and exhibiting 

 life and motion. 



Such being the effects produced on these animals after 

 distention, it may be inferred, that if removed at once from 

 their natural habitat into salt water, they would not plump 

 up, as in fresh ; and I find that when so treated they become 

 even more shrivelled than before ; and also, that they will 

 then continue to live for several days, a circumstance which 

 I have found very convenient, as they can thus be preserved 

 for observation or experiment.f On placing a number of re- 

 cent specimens in skimmed milk, I found that no absorption 

 took place, they remained quite flaccid, and on the following 

 day seemed perfectly dead, but on being laid in fresh water 

 they plumped up as much as if they had been immersed in 

 it at first. In water slightly sweetened with sugar, and in 

 weak solutions of sulphate of soda, sulphate of magnesia, 

 carbonate of soda, and nitrate of potash, the same results fol- 

 lowed as in solution of common salt. 



I may remark here, that the imbibition of water is not con- 

 fined to the Echinorynchi. I have observed it scarcely less 

 remarkable in some of the cavitary Entozoa, especially the 

 Cucullani, and from reiterated observation, I am satisfied that 

 the disruption of the body, with exclusion of the ovaries, and 

 a loop of the intestine, which has so often been remarked,! 



* Vide Zool. Dan. vol I. p. 47. 



f By this simple expedient I have been enabled to preserve various spe- 

 cies, such, for instance, as the delicate Bothriocephali of the cartilaginous 

 fishes, for a day or two living, whereas in fresh water they scarcely survive 

 an hour. The Echinorynchus Acus I have kept living for even eight days. 



X Rudolphi has the following remark relating to the Cucullanus elegans, 

 a species found in the perch, and some other fresh water fishes. " Matrem 

 prolam suam per vulvam edidisse nunquam vidi, neque alius quidem ob- 

 servavit, sed ipsa loco incerto rumpitur, et oviductus prolapsi pluribus locis 

 pariter disrupti motu undulatorio eandem effundunt, ovorum tunicis adhce- 

 rentum." Entoz. Hist. Nat. vol. II. part I. p. 105. 



