THE MYXOSPORIDIA, OR PSOROSPERMS OP FISllES. 269 



pares with the observations of Aiiorbach and others,' but without 

 affirming- Aiierbach's interpretai ion of dichromopliihsin as indicative 

 of nuclear bisexuaUty. 



Habitat. — Host: Biifo Icntiginosus Shaw (a toad). The single speci- 

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

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

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

 linally 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 careful 

 examination, however, a faint flutter of the pleiu^il wall over the heart, 

 but no respiration. 



Dr. Ohlmacher has kindly informed me (letter, 1893) that the locality 

 whence all the specimens were obtained is Syc^amore, DeKalb County, 

 Illinois. Three more specimens of 7^. Icntifjinosus collected there July, 

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

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

 same condition was found in the males.) 



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

 lumen of the urinary tubules; never withi-i the epithelial cells, which 

 latter never siiow the nuclear metamorphosis occurring with the intra- 

 cellular Sporozoa; occasionally found in sections among the blood cor- 

 puscles in the large blooil vessels, it being here ini])ossible to say that 

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

 never found in 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. 



Microscopic technique. — Fixation by absolute alcohol or Flemming; 

 imbedding in xylol-paraffin; affixing by tlie water-albumen method; 

 staining with various anilins. 



Mode of infection. — As to the origin of the i.iyxosporidian infection, 

 it can only be conjectured, Ohlmacher says, that it nuist have occurred 

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

 ascended the urinary passages. It is i^robable 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. 



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

 serous fluid derived from the abdominal cavity and the subcutaneous 

 lymph siinises; to this fluid the distension Avas in large part due. The 

 organs showed nothing unusual, except that the urinary bladder was 



' Ohlmacher gives reference as follows: Anerbach, Uehcr ciuen sexuellen Gcgeii- 

 satz iudorc^roinojihile dcr Keimsiibstanzen ; Sitzgsber. k. preiiss. Akad. d. Wissensch. 

 Berlin, Juno 25, 1891, p\). 713-750; Adamkiewicz;, Untersnchung ii. d. Krebs u. d. 

 Princip. seiner Hehnndliing, Wicn u. Leii)/ig, 1893; Xoeggorath, Heilriige z. Stniktiir 

 n. Entwickelungd. Carciuoms, VVieabadeu, 1892; Watasd, Journ. Morphol., 1892. vi, 

 pp. 481-493. 



