176 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



6. Gentis et sp. incert. PI. 4, figs. 2-8; pi. 5, figs. 1-11. 



Pilzsporeii of Cyclops, Chuis, 18G3, Die froilobeiulen Copepodon, Leipzig, p. 

 87; Mijxosporidiaf of Cyclops, of Diapt. cnendeits aud of Diapt. ricliardi, 

 Schmeil, Beitriige z. Keuutu. d. freilp.benden Copepoden Deutschlands, 

 Ztsclir. f. Natnrvviss. Halle, 1891, Lxiv, pp. 19-21; Entoparasitischo 

 Scblauche der Cj'clopideii Schowialcoff, Ueber eiuige elito-, aud euto- 

 parasitischo Protozoeu der Cyclopideu, Bull. See. Imp. Nat. Moscow, 

 1893, pp. 2, 15-26, pi. 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, sulficieiit notes on 

 these bodies unfortunately are lacking, so tliat I am compelled to leave undeter- 

 mined tbeir nature and tlieir relation to Farkistuphytonovatiim, so full of significance 

 through the disease of the silk-worm. 



To bis quotation of part of the abov'e Sclimeil (p. 21, footnote 1) 

 adds : 



" Thb organisms ohserved by me are, however, certainly not spores of fungi" [italics his 

 own]. 



Scbmeil 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. cmruleus Fisch. and D. 



ricliardi Schmeil. 



As this parasite is relatively very frequent — though absolutely (standig) 

 [Page 20] rare — one soon learns to tell the affected animals with the naked eye by 



their striking gray color. Their movements are unafTected. Microscopic 

 examination shows individual parts of the body strikingly dark (in Cyclopids and 

 D. ricliardi Schm., black; D. cwruleus Fisch., dark brown); often the whole thorax, 

 the abdomen, and even the tail, the first antonnie, and natatory feet are either 

 entirely or partly filled by this dark mass. On closer examination this dark color 

 is seen to be due to an innumerable host of small fusiform or crescentic corpuscles, 

 whose form (plainly perceived by pressure-rupture of the copepod shell) places 

 them as psorosperm-like bodies. From Schmiil's description and drawings, Biitschli 

 considered thcra 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 

 difierentiation 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 Avas 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 streniiits Fisch. 

 taken from under the ice of a pool (clay ditch near Schlettau). 



'Place not stated; or whether published. 



