515 



ulcerated spots in the body wall. These were fixed in Flemming's 

 fluid (stronger formula), sublimate acetic, sublimate, and picro-acetic 

 (Boveri). They were sectioned and stained in iron haematoxylin, 

 Flemming's triple stain, and in thionin with, a counter stain of eosin. 



A superficial examination did not reveal any cysts or aggregates 

 of spores so characteristic of the majority of the Myxosporidiida and 

 in the more careful subsequent examinations although innumerable 

 quantities of spores were found distributed throughout the body, they 

 were not aggregated in cysts, while in no case did I succeed in finding 

 thread-bearing capsules which distinguish the spores of the Myxospo- 

 ridiida from those of all other Sporozoa. The various methods recom- 

 mended by Gurley (1893) *, and Thélohan (1892) for demonstrating 

 the presence of the capsule and its contained thread were tried with 

 no result. 



The spores were found in all parts of the fish including all of 

 the organs selected for examination. In the intestine they formed 



% f f 



& 



ê 



*. 



A B 



Fig. 1. Spores and sporozoite-formation. A typical spores; B Sporozoite- 

 formation; C Isolated sporozoites. Camera lucida X 2000. 



large masses together with the intestinal bacteria; they were found in 

 the lymph spaces surrounding the intestine, liver, kidney, and other 

 organs of the viscera; in the muscle bunoles of the body wall; in the 

 mesenteries and connective tissue throughout the body ; in the cavities 

 of the gall- and swimming-bladder, and in the lumina of blood vessels. 

 They were, in short, universally distributed about the cavities and 

 spaces of the diseased fish. They were not- seen however in the glan- 

 dular tissues in general, although they were occasionally met with in 

 the kidney. The testis however, seemed to be the main seat of the 

 spores, and was literally crowded with them, especially in fish from 

 four to five inches in length. 



The spores (fig. I A) are very small (2 to 3 <u), pyriform in shape 

 and of homogeneous appearance. The substance of which they are 

 composed shows a decided affinity for the chromatin stains, especially 



U. S. Fish Commission, Report 1893. 



38* 



