THE MYXOSPORIDIA, OR PSOROSPERMS OP FISHES. 247 



Sporoplasm: In tlie preparation this had nui to a mass with phiiiily 

 visible coarser and finer granules. Sporoplasm traceable only to the 

 root of the tail, Avhere its lateral borders converge sharjjly; in the 

 untailed forms it is rounded off posteriorly. 



No nucleus was discovered; bodies staining with hajraatoxylin, 

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

 resolved by a Leitz J^ 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 i^arts) 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 Pi'o- 

 tozoa iS^o. IGGl in the collection of the Konigliches Museum fur N'atur- 

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

 the sporoplasm. 



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

 of February, 1802. 



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

 is not identical with, 3L scMzurus. This species also bears a great 

 similarity to Lieberkiihn's figures (in Biitschli) ofM. psorospermicus, but 

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

 present form to be identical with M. creplini, as the shai)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 Thdlolian, 1892. 



(Cf. tailed psorosperms of kidney of Gastcrosteua aculeatus, Lieberkiilin, 1854, 



Miiller's Arcliiv., 1854, p. 3.57 (see p. 185); myxosporidian spores of G. 



acideaius and G. pungitius (pars) Th^lohan, 1890, Anual. de Microgr., ii, 



pp. 198-200, 209, pi. 1, fig. 1 ; ih. (pars) Th<<lolian, Conipt. Rend, hebdoiu. 



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

 Hcnneguya hrevia Tbelolian, 1892, I?ull. Soc. iihilomat. Paris, iv, p. 177. 

 Myxohohis brevis, Gurley, 1893, IJiill. U. S. Fish Com. for 1891, xi, p. 416. 

 Henneguiia brevis, Braun, 1893. Centralbl. f. Bakt. u. Parasitenkde, xiv, p. 739. 

 Myxobulus brevis, Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. 



Cyst and myxosporidium not mentioned. 



Spore. — Small; length, 15 /.i; breadth, 5 to 6 /<; anterior portion more 

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



Hahitat. — Renal tubules and ovary of Gasterosteus aculeatus (sticlc- 

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

 back); all^cZe Thelohan, letter, 189;i. 



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



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

 by the expulsionof a small mass of gluey and viscous matter in which the micro- 

 Boopist ea-silj' recognizes psorosperm.s, aborted eggs, etc. 



