OF THE CYSTIC ENTOZOA. 97 



its enclosure alive. The specimens I examined were from the 

 membranes of the brain. 



" This observation was made in Edinburgh, and, on going to 

 London soon after, I mentioned the fact to Mr. Owen ; and I 

 have been accustomed to take notice of it in my lectures ever 

 since, suggesting at the same time that it would be well to search 

 for them, or for analogous parasites, in the nerves of other ani- 

 mals, as it was not likely that the gadus tribe of fishes should be 

 the only example. Indeed, unless my memory deceives me, some 

 one has met with something of the same kind in the nerves of 

 the frog ; and Valentin has seen the eggs of Distoma in the ver- 

 tebral canal of a foetal sheep. When I learned that the oval bodies, 

 which all must have seen in the cellular tissue of the palm of the 

 hand and fingers, were connected with the nerves, I at first ima- 

 gined they might be entozoa, (having been led to make just the 

 converse of your conjecture,) but Mr. Marshall, formerly of our 

 Museum, having examined these " Pacinian" bodies two or three 

 years ago, (quite independently of any suggestion from me,) I 

 found nothing to confirm this conjecture on his showing me their 

 structure. 1 have since seen Henle and Kolliker's memoir, which 

 includes the substance of Pacini's observations. 



" Rudolphi, as far as I know, never examined the structure of 

 the spheroidal bodies of Monro ; and the only notice of them 

 which I have met with in his writings (to which he did not refer 

 me) is in his Historia Naturalis Entozoarum^ Vol. ii. Part 2, page 

 277, when, under the head of Dubious Entozoa, he enumerates 

 an object described and figured by J. Rathke, under the name 

 of " Hydatula Gadorum," which that observer found in the pia 

 mater of the Gadus Morrhua and G. Virens, often in great num- 

 bers, and which appeared to be a vesicle containing a worm. The 

 nature of the parasite was doubtful, but supposed in some degree 

 to resemble that of a cysticercus, and hence the name applied to 

 it by Rathke, but Rudolphi denies that it is a cysticercus, though 

 he does not know to what genus to refer it, he adds 6 an Cucul- 

 lanus.' " 



This entozoon, as stated by Monro, is found in great numbers 

 in the gelatinous substance which surrounds the brain, spinal 

 cord, and semicircular canals, in the cod, haddock, and whiting. 



