THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 269 



pares witli the observations of Auerbacb and others,^ but without 

 affirmiug- Aucrbach's iuterpretaiiou of dichroinophilism as indicative 

 of nuclear bisexuabty. 



Habitat. — Host: Bufo lentiginostis Shaw (a toad). The single speci- 

 men was a large female, sent with a lot of frogs (which latter sliowed 

 no unusual mortality) from the country to the laboratory early in 

 September. A gradual increase in size took place in the toad and 

 finally became particularly noticeable, but this was unconsciously 

 ascribed to development of ova. About November 15 the specimen 

 was noticed lying on its back, apparently dead, showing on carefid 

 examination, however, a faint flutter of the pleural wall over the heart, 

 but no respiration. 



Dr. Ohlmac'her has kindly informed me (lctt('r, 1893) that the locality 

 whence all tlie specimens were obtained is Sycamore, DeKalb County, ~ 

 Illinois. Three more specimens of B. lenticjinosus collected tliere July, 

 1893, showed the same myxosporidian species, but not in such numbers. 

 All of the toads thus far examined have been females. (Later the 

 same condition was found in tlie males.) 



Seat: xVlmost invariably present in larger or smaller groups in the 

 lumen of the urinary tubules; never within the epithelial cells, which 

 latter never show the nuclear metamorphosis occurring with the intra- 

 cellular Sporo.z'oa-, occasionally found in sections among the blood cor- 

 puscles in tlie large blood vessels, it being here impossible to say that 

 it might not have boju due to displacement during the technique; 

 never found iu the glomeruli; occurring sparingly in the collapsed 

 folds of the urinary bladder, always on the bladder surface, never 

 imbedded in the bladder wall; also free in the urine. 



Microsc.'pic teGhiiique. — Fixation by absolute alcohol or Flemming; 

 imbedding in xylol-paraffin; afiixing by the water-albumen method; 

 staining witli various anilins. 



Mode of infection. — As to the origin of the myxosporidian infection, 

 it can oidy bo conjectured, Ohlmacher says, that it must have occurred 

 by way of the cloaca to the bladder, and from here the parasites 

 ascended the urinary passages. It is probable that in this case the . 

 parasite did not reach its adult condition in its batrachian host, but 

 here only passed one stage of its development, the spore stage. 



Pathohxjy. — Abdomen containing a large quantity of straw-colored, 

 serous fluid derived from the abdominal cavity and the subcutaneous 

 lymph sinuses; to this fluid the distension was in large part due. The 

 organs showed notliing unusual, except that the urinai-y bladder was 



' OMraaclier gives reference as follows : Anerbacli, Uebcr einen sexuellen Gegen- 

 sutz in der chromophile der Keiuisubstanzen ; Sitzgsber. k. prens.s. Akad. d. Wissenscli. 

 Berlin, Jnne 25, 1891, pp. 713-750; Adamkiewicz, Untersucliuug ii. d. Krebs n. d. 

 Princip. seiner Heliandlnn,i>-, Wien u. Leipzig, 1893; Xoeggeratli, Heitriige z. Struktur 

 n. Entwickelnngd. Carciuoms, Wiesbaden, 1892; Watas^, Jonrn. Morphol., 1892. vi, 

 pp. 481-493. 



