THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 271 



From Dr. Wliiuery's paper the following data are condeused: 

 [Page 660] All the toads examined (ahntit a dozen in all) were from Sycamore, Do Kalb 



County, 60 miles west of Chicago.- The toads were kept in the laboratory 

 sink, and taken from this, from time to time, for examiuaiion. 



The extent of the infection must vary with the surroundings and env^ironment of 

 the animals. Seven toads examined— 2 males and 5 females — showed 1 male and 4 

 females infected. It is quite probable tliat the uiortality was increased by the con- 

 finement in a comparatively small space. During the confinement the toads became 

 stupid, moved about but little, and in 2 or 3 days began to die, 1 dying every day 

 or two. Some of them liA^ed about 3 weeks. Before death no change in external 

 ap])earance was noticed, except in some cases a distension of the abdomen. Post 

 mortem some increase in amount of peritoneal fluid vv^as usually noticed, but in the 

 toads examined by Wliiuery this was never so large in amount as in the toad examined 

 byOhlmacher. The abdominal viscera showed signs of congestion; the intestines 

 being usually distended Avith gas and the kidneys enlarged and in a congested state. 

 The parasites were found only in the tubules and in the urinary bladder, and in the 

 spore stage. Ohlmacher's view that they probably kill by mechanical pressure seems 



very plausible on account of the large number of pai'asitesiu the tubules. 

 [Page 661] This number variss in difierent specimens; sometimes only scattering 



tubules, in other cases large areas of tubules being filled with parasites. 

 They were never found in the glomeruli or epithelial cells. In the bladder they Avere 

 found in the folds of the mucous membrane. Ohlmacher has found them in urine 

 collected during chloroform narcosis, in a clean basin. 



Detailed Morphology of Spore. — Length about 6 /i; breadth about 8 y^; size slightly 

 varying in the same prejiaralion. Sliape, slightly oval. Shell, showing a distinct 

 striation, the stri.'e appearing to proceed from the shell of each lateral half and to 

 center at the valve-junction, midway between the anterior and posterior ends. 

 Spore showing at each end a sliglit projection,' running between which 2 points is 

 the faint transparent ridge, marking the valve-junction. The projections represent 

 the vertical opiical section of the ridge. The spore is thus composed of 2 valves, 

 their junction plane dividing the sjiore into 2 symmetrical halves. Two small knob- 

 like thickenings (which show well in the fresh, unstained spore) can be seen at the 

 anterior projection, 1 belonging to each valve. The spores often show cleavage at 

 the anterior end along the line of the valve-junction. Capsules 2, round, 3 u to 3'5 

 fj. on an average, situate at the anterior end, 1 in each valve. A filament arises from 

 each capsule, and, penetrating the shell, leaves the spore at the anterior end. The 

 capsules seem to have the power of projecting and drawing in these filaments. 

 Length of filaments often more than 4 t.o 8 times the diameter of the spore. Just 

 after entering the spore, before reaching the capsule, they often appear in a spiral 

 roll preparatory to being coiled in the capsule. Sporoplasm situated in the poste- 

 rior end, extending to the sides, in form approaching a crescent; not completely 

 filling the space posterior to the capsules; under high powers (-i^ Leitz) appearing 

 homogeneous and finely granular; showing in fresh preparations the more highly 

 refractive grannies designated nuclei bj- Tht^lolian; these apparently vary in number 

 and position in fresh spores, and never appear in hardened and stained preparations.* 

 A vacuole could not be discovered in this species. 



'" Termed by Gurley the 'micronate [mncronate] projection,'" This name was 

 employed by me in a letter in a general sense only {a mucronate projection) and was 

 not intended as an additional special term. 



-Ohlmacher had only hardened material, a fact which, Whinery thinks, explains 

 his failure to find nuclei. I can not believe, from Dr. Vv hinerys description, that the 

 bodies he calls "nuclei" are really such, since t\\&j disappear entirely in hardened and 

 stained specimens. Although I have not seen Dr. Whinery's material, I venture to 

 suggest the possibility of their being fat globules. 



