522 Notices of Irish Entozoa. 



during its eversion their points are more directly pressed a- 

 gainst the intestinal coat, and when the entire proboscis is 

 retracted at once, a greater effect will be produced, the resis- 

 tance being opposed to their long axis. When the animal 

 wishes to let go its hold of the intestine, and shift its quar- 

 ters, it has only to reverse the order of action by which it be- 

 came fixed. 



It is probable that the Echinorynchi soon become sensible 

 of the death of the animal they inhabit, which I would infer 

 from the circumstance of their being generally found loose in 

 the intestine. I have seen the present species sometimes ad- 

 hering in considerable number, but much more frequently ly- 

 ing detached, and often many individuals clustered together 

 so as to occupy almost the whole width of the intestine. It 

 is difficult to conceive how such numbers as often occur can 

 adhere to the intestine without causing much mischief, and 

 yet the fishes in which they are most numerous, seem to be 

 perfectly healthy, and well nourished. I have seldom exam- 

 ined a codling, without obtaining from ten to one hundred 

 specimens of Echinorynchus Acus, and on the first of the 

 present month, I found 216 in one which was under two lbs. 

 weight, and on the fourth, in another a little larger, I counted 

 219. I have not yet observed it in the haddock, which I 

 attribute to its feeding on Ophiurce, with fragments of which 

 the stomach and intestines of those I have hitherto examined 

 were literally crammed. These hard bodies act mechanically 

 as a vermifuge, and to a similar cause I believe it to be owing, 

 that I have not yet observed an Entozoon in the alimentary 

 canal of the gilaroo trout, or the thick-lipped gray mullet, 

 {Mugil Chelo), both of which subsist principally on Testacea.* 



Ova. — When the female Echinorynchus, distended with wa- 

 ter, is either cut across, or an incision made into its side,' a 

 fluid rushes out, which to the naked eye has the appearance 

 of a milky cloud, but under the microscope this is found 

 chiefly to consist of thousands of ova, of a long, linear, ellip- 

 tical form, transparent, and of various dimensions, some be- 

 ing many times larger than others. Intermixed with these 

 spicular ova, are observed rounded or oval bodies, of a much 

 greater diameter, and having a spongy or cellular appearance, 

 (/. 24, c). Of the spicular ova the smaller are transparent 

 throughout, but the largest, which seem to be in their full 

 state of developement, have an appearance under a magnify- 



* See the excellent account of the Mugil Chelo given by my indefatiga- 

 ble friend, W. Thompson, Esq., in the first volume of the Annals of Na- 

 tural History, page 350, et> seq. 



