176 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
6. Genus et sp.incert. Pl. 4, figs. 2-8; pl. 5, figs. 1-11. 
Pilzsporen of Cyclops, Claus, 1863, Die freilebenden Copepoden, Leipzig, p, 
87; Myxosporidia? of Cyclops, of Diapt. ceruleus and of Diapt. richardi, 
Schmeil, Beitriige z. Kenntn. d. freilebenden Copepoden Deutschlands, 
Ztschr. f. Naturwiss. Halle, 1891, Lxtv, pp. 19-21; Entoparasitische 
Schliuche der Cyclopiden Schewiakoff, Ueber einige ekto-, and ento- 
parasitische Protozoén der Cyclopiden, Bull. Soc. Imp. Nat. Moscow, 
1893, pp. 2, 15-26, pl. 1, figs. 17-34. 
Claus says: 
The bodies formerly! designated by me ‘‘spores of fungi,” with which I have many 
times found the body-cavity of Cyclops entirely filled, I have unfortunately not been 
able to observe again in later times. From the earlier period, sufficient notes on 
these bodies unfortunately are lacking, so that I am compelled to leave undeter- 
mined their nature and their relation to Parhistophyton ovatum, so full of significance 
through the disease of the silk-worm. 
To his quotation of part of the above Schmeil (p. 21, footnote 1) 
adds: 
“<< The organisms observed by me are, however, certainly not spores of fungi” [italics his 
own]. 
Schmeil further says (abstract): 
I have observed another parasite in nearly all the Cyclops of the Halle 
[Page 19] region, further in the specimens seen of Diapt. cwruleus Fisch. and D. 
richardi Schmeil. 
As this parasite is relatively very frequent—though absolutely (stdéndig) 
[Page 20] rare—one soon learns to tell the affected animals with the naked eye by 
their striking gray color. Their movements are unaffected. Microscopic 
examination shows individual parts of thé body strikingly dark (in Cyclopids and 
D. richardi Schm., black; D. ceruleus Fisch., dark brown); often the whole thorax, 
the abdomen, and even the tail, the first antennw, and natatory feet are either 
entirely or partly filled by this dark mass. On closer examination this dark color 
is seen fo be due to an innumerable host of small fusiform or crescentie corpuscles, 
whose form (plainly perceived by pressure-rupture of the copepod shell) places 
them as psorosperni-like bodies. From Schmeil’s description and drawings, Biitschli 
considered them Myxosporidia. Size very variable; besides very small corpuscles, 
one meets with larger ones 3 or 4 times the smallest, but the sizes of all those 
occurring in the same individual are always nearly equal. These corpuscles appear 
to possess a firm membrane, immediately within which a clear zone is situated. No 
differentiation of contents could be observed. Water and glycerin do not alter the 
form. 
Origin of these corpuscles unknown; repeated attempts to infect 
[Page 21] healthy animals failed. Multiplication.by division seems proven by the 
occurrence of two or several corpuscles lying close together, often in con- 
tact lengthwise; often, however, with their blunt poles surrounded by a common 
membrane. Therefore,in case the explanation generally given is correct, a double 
division in the transverse and longitudinal axes appears to take place. 
On account of the lack of infected animals it is exceedingly difficult to reach safe 
conclusions concerning these conditions. 
Such was the state of the subject when Schewiakoff began his investi- 
‘gations. The following are his results: 
This condition has been observed at all seasons, first on Cyclops strenuus Fisch. 
taken from under the ice of a pool (clay ditch near Schlettau). 
'Place not stated; or whether published, 
