PARASITES OF PROTOZOA 1065 



of the tube that remains external to the cell swells and becomes a 

 sporangium, in which by simultaneous partitioning from 20 to 100 zoo- 

 spores are produced. Most parasitized colonies had not more than 25 to 28 

 normal cells, and heavily parasitized colonies may be destroyed. 



Polyphagus euglenae, whose structure and life history have been de- 

 scribed by Nowakowski (1876), Dangeard (1900b), and Wager 

 (1913), appeared at various times in cultures of Euglena, which were 

 destroyed in a few days. Serbinow (1907) at Petersburg, and Skvortzow 

 (1927) in East Mongolia found it parasitic on Chlamydomonas. The 

 parasite germinates free in the water, and a single cell, by branched 

 haustoria, may attack many flagellates. A haustorium perforates the cell 

 wall, branches, and the cell contents rapidly disintegrate. A sporangium 

 develops as an outgrowth from the protoplast, and produces a variable, 

 usually very large, number of uniflagellate zoospores. Polyphagus is one 

 of the few Chytridiales in which sexual reproduction has been satis- 

 factorily demonstrated. A zygote is formed by the fusion of two vegeta- 

 tive cells, and becomes a resting spore, with smooth or spinous mem- 

 brane. 



Skvortzow (1927) reported two other Chytridiales from Eudorina 

 elegans m Manchuria: Phlyctidium eudoYinae n. sp. and Dangeard'm 

 mamillata. The latter was originally described by Schr5der from Pan- 

 donna. Phlyctidhnn is epibiotic, with a haustorium penetrating a cell. 

 The sporangia of Dangeard'm are located in the gelatinous sheath of the 

 volvocid. 



Lagenldium trichophryarum, which belongs near the Chytridiales in 

 the Ancylistales, was described by G5nnert (1935) in Trkhophrya 

 epjstylidis. The parasite, which appeared once in abundance, was fatal 

 to the suctorian. Lagenidium is rare in Protozoa. Cook's revision of the 

 genus (1935), which is in the same number of the Avchiv fur Protisten- 

 kunde as Gonnert's article, reports no species from them; the habitat is 

 filaments of green algae, diatoms, pollen grains, and rhizoids of mosses. 



Filamentous appendages on the posterior end of certain large fresh- 

 water amoebae (Fig. 221) have long been known. Leidy (1879) ob- 

 served them, and was uncertain as to their nature, regarding them at 

 first as a bundle of mycelial threads dragged behind Amoeba proteus, 

 but finally concluding that they were structural elements of the amoebae. 

 He made the presence of these appendages diagnostic of the new genus 



