THE MYXOSPORIDIA,, OR PSOROSPERMS OF FISHES. 247 



Sporoplasm: lu the preparatiou this had run to a mass with phiiiily 

 visible coarser and finer granules. Sporoplasm traceable only to the 

 root of the tail, where its lateral borders converge sharply j in the 

 untailed forms it is rounded off posteriorly. 



No nucleus was discovered; bodies staining with hsematoxylin, 

 borax-carmine, bismarck brown, gentian violet and Kernschwarz were 

 resolved by a Leitz Jq immersion into coarse granule-heaps, having 

 little similarity to nuclei. 



Microscopic technique. — Material received fresh ; the pathologic mate- 

 rial was placed in glycerin and water (equal parts) and fixed with some 

 drops of saturated sublimate solution ; 14 days later it was transferred 

 to 50 per cent, and subsequently to 70 per cent alcohol. In alcohol the 

 eggs remained soft. In this form the material was catalogued as Pro- 

 tozoa No. 1661 in the collection of the Konigliches Museum, fiir Natur- 

 Jcunde. Bismarck brown stains the capsules only; borax carmine, only 

 the sporoplasm. 



Habitat. — Ovary of Lucius lucius (pike) collected at the beginning 

 of February, 18DL>. 



Remarks. — Of Miiller's forms, the present species resembles most, but 

 is not identical with, M. scliizurus. This species also bears a great 

 similarity to Lieberkiihn's figures (in Biitschli) of il/. psorospermicus, but 

 here too, specific differences exist. On the contrary, he believes the 

 present form to be identical with 31. crepUni^ as the shaj)e and size of 

 the two agree well; it is, however, to be noted that the thickness is 

 seldom as great as that of the last-named species. 



70. Myxobolus brevis Thelohau, 1892. 



(Cf. tailed pHorosperms of kidney of Ga^ferostetis aculeatus, Lieberkiihu, 1854, 



Miiller's Arcbiv., 1851, p. 357 (see p. 185); rhyxosporidiau spores of G. 



acuUaims and G. pungiims {pars) Th^lohan, 1890, Auual. de Microgr., ii, 



pp. 198-200, 209, pi. 1, fig. 1 ; ih. (pars) Tli61ohan, Conipt. Rend, hebdom. 



Soc. Biol. Paris, ii, p. 604.) 

 Eenneguya Irevis Tbelobau, 1892, Bull. Soc. pbilomat. Paris, iv, p. 177. 

 Myxoholus brevis, Gurley, 1893, Bull. U. S. Fisb Com. for 1891, xi, p, 416. 

 Sennef/uya drevis, Brauu, 1893. Ceutralbl. f. Bakt. u. Parasiteukde, xiv, p. 739. 

 Myxoholus brevis, Braun, 1894, Ceutralbl. f. Bakt. u. Parasiteukde, xv, p. 87. 



Cyst and myxosporidium not mentioned. 



Spore. — Small; length, 15 yu; breadth, 5 to 6 yu; anterior portion more 

 swollen; tail very short, caudal index hardly 0-50. 



Habitat. — Renal tubules and ovary of Gasferosteus aculeatus (stick- 

 leback) ; renal tubules and ovary of Fygosteus pungitius (9-spined stickle- 

 back); ^Wfide Thelohan, letter, 1893. 



Effects. — The following from Thelohan probably refers to this species: 



At the moment of tbe exi)ulsiou it is not rare to see tbe normal spawning replaced 

 by tbe expulsion of a small mass of gluey and viscous matter iu wbicb tbe micro- 

 scopist easily recognizes i)sorosperms, aborted eggs, etc. 



