OBSERVATIONS AND EXPERIMENTS ON EUGLENOIDINA. 



Rana pipiens a species of Phacus was noted that resembled in 

 size and shape, Phacus pleuronectes. They were about 42 fj, 

 long and 32 /j. broad, oval in shape with an uncinate posterior 

 spike about 6.5 M long, a longitudinal groove extending anteriorly 

 from the posterior end, a longitudinally striated periplast, and a 

 large number of green chromatophores, as indicated in Fig. 5. 

 These organisms remained alive and active for 48 hours in in- 

 testinal contents that were sealed under a cover glass with vase- 

 line. 



XII. The Effects of the Presence oj Euglenoids on Other Intestinal 

 Protozoa. No apparent effects on the number and distribution 

 of other intestinal protozoa were noted due to the presence of 

 Euglenoidina. There was, however, a change in the color of 

 many of the opalinas. As a rule Opalina is almost transparent 

 when studied with a compound microscope but whenever eugle- 

 noids were abundant many of them took on a greenish yellow 

 tinge. This was true in the tadpoles of both Rana pipiens and 

 the toad and was very noticeable in the tadpoles that were fed 

 on free living euglenoids. Evidently nutrition in Opalina in the 

 presence of chlorophyll bearing bodies is a process whereby some 

 of this coloring matter is taken in thus causing a greenish tinge. 



XIII. The Parasitic Habit among the Euglenoidina. Only a 

 few of the Euglenoidina have been described as parasitic in habit. 

 Prof. L. B. Walton mentions two species of the genus Astasia in 

 his monograph on the Euglenoidina (Walton, 1915) and has 

 called my attention (in litt.) to other members of the order de- 

 scribed by Alexeieff (1912) and Nieschultz (1922). Astasia cap- 

 tiva is endoparasitic in Catenula lemnae, and A. mobilis in the 

 egg sacs and digestive tract of Cyclops a condition that has led 

 to the suggestion by Alexeieff that parasitic Sporozoa may have 

 originated in this way. Nieschultz describes a species of Astasia 

 from the digestive tract of a fresh-water nematode, Nilopus gra- 

 cilis, but does not give it a specific name. Haswell (1907) re- 

 ported the occurrence of a euglenoid inside the cells of a rhabdo- 

 ccele Turbellarian. Alexeieff reports the discovery of small, 

 living, active euglenoids, Euglena sp. and Phacus longicauda, in 

 frog tadpoles and states that Brumpt also showed him specimens 

 containing hundreds of Eiiglence. The green color and stigma 

 of these were as bright as in free-living specimens. This, accord- 



