SEA-TTSHERIES LABORATORY. 127 



are always (at first) cell-parasites, with very minute 

 spores possessing only one polar-capsule, invisible in 

 the fresh condition. In all cases the parasites were 

 found in the gut-wall, ranging, indeed, from the 

 (esophagus to the rectum. The cysts were lodged 



according to the author, either in the muscular or 

 connective tissue (sub-mucosa), or else projecting 

 into the coelomic cavity, and only covered by the 

 peritoneal epithelium. They were also found under the 

 peritoneum investing the liver, and in the mesenterial 

 folds in which the blood-vessels run, but were completely 

 absent from the other organs, spleen, kidney, &c. "With the 

 exception of certain species of Myxobolus, this invasion of 

 gut is quite unique among Hyxosporidia of fishes, the 

 Myxobolidse causing the above-mentioned devastating epi- 

 demics, usually occurring in the tissue of the liver, spleen, 

 kidneys, bladder, &c. Hagenmiiller goes on to describe 

 briefly the minute anatomy of the parasites and their 

 relation to the host's tissues as seen under a high power, 

 and reference to one or two points iu his account will be 

 found below. 



The next record of intestinal cysts in a flat-fish is 

 that by Johnstone (3), who describes and figures Sporo- 

 zoan cysts from two specimens of the plaice (Pleuronectes 

 Ijlatessa). On examination of sections like that from 

 which the author's fig. 2 was drawn, prepared from 

 material which he was kind enough to forward me, I had 

 no hesitation in deciding that these were also cases of a 

 Glugea* infection. llagenmiiller did not give the size 

 and shape of the spores of G. stephani — the principal, 

 though rather arbitrary, criterion of specificity among the 



* There is some doubt as to which of the two generic names, 

 Glugea ov Nosevia. should be employed, so I have retained the former, 

 which is well known and established. 



