1072 PARASITES OF PROTOZOA 



evidence that material may be extracted from tlie host. Many parasitized 

 chilomonads had lost their flagella, but otherwise they were apparently 

 not injured. Bodo perjorans was rarely seen free from attachment. 



Gregarella jahrearum, studied by Chatton and Brachon (1936) and 

 Chatton and Villeneuve (1937), shows few characteristics that can be 

 used for taxonomic purposes; yet it was considered by them to be a 

 much regressed flagellate, representative of a new group of zooflagellates, 

 the Apomastigina. It is reported to undergo a cycle of development as 

 follows: ingestion by Fabrea, fixation to the wall of a vacuole, with 

 growth and transverse division, discharge from the body and fixation 

 to the ectoplasm around the cytopyge, where feeding and slower multi- 

 plication take place. The fixed parasites are claviform with the large 

 end adherent, are capable of slow changes of shape, contain large 

 refractile inclusions, and have no flagella or other permanent differentia- 

 tions. 



The parasite on Colpoda cucullus (Fig. 222C), observed in a hay 

 infusion by Gonder (1910), recalls in some ways certain of these 

 ectozoic flagellates. The organism has a round or oval figure, with the 

 narrowed end extended through the pellicle. The nucleus is single, 

 vesicular, with a large endosome — not an ordinary ciliate type. No fla- 

 gella or cilia were seen. Gonder was vague about its relationships. 



Small mastigamoebae were recorded by Doflein [Lehrbuch, 1909, 

 and later editions) as not infrequent parasites of Stentor coeruleus; and 

 he figured an instance of heavy infection. Infected ciliates were faded 

 and somewhat contracted, and eventually often burst. 



Flagellates were found in Craspedophrya rotunda and other Suctoria 

 by Rieder (1936). The incidence was high in a culture of the first 

 species and light in four other species. At first only a few Craspedophrya 

 were parasitized, but in a few days many were infected. The organisms 

 were colorless, actively metabolic, from 6 to 11 microns in length, and 

 had two flagella 1.5 times the body length, of which one was anterior 

 and the other trailed. They entered the suctorian through the envelope, 

 sometimes at the thinnest place, as over the brood chamber from which 

 a swarmer had escaped, but also elsewhere. They were observed swim- 

 ming about actively within the pellicle, taking up suctorian plasma, and 

 undergoing binary fission. Eventually the flagellates often rounded up 

 and lost the flagella; some left through the pellicle, probably in the way 



