STUDIES ON EUGLENAMORPHA HEGNERI. i6l 



movements, then quickly assume the normal elongated shape, swim 

 actively for a while, then gradually slow down till dead. The pel- 

 lucid variety with its additional flagella is even more active than 

 the green one, as one might reasonably expect. In cultures where 

 they were able to persist, they often came to rest at the edge of the 

 drop toward the window, the body remaining practically motionless 

 while the flagella continued their activity. In these individuals the 

 flagella usually assumed a position near the body instead of ex- 

 tending out in front. In fresh material examined in salt solution 

 or Ringer's solution, they have been seen to attach themselves by 

 one flagellum while the other two continued to vibrate along the 

 side of the body, and within the rectum a similar behavior has been 

 seen. The activity of the flagella along the sides of the body 

 might have a respiratory function as well as serve to bring food 

 (in solution) to the body for absorption. 



As Hegner ('23) has found, Euglenamorpha is positively photo- 

 tropic. 



DISCUSSION. 



Since Hegner ('23) has found this new flagellate in New York 

 and Maryland and the writer in Pennsylvania and at Woods Hole, 

 Mass., it would seem to be rather widely distributed. It is sur- 

 prising, therefore, that its existence has not been noted by other 

 observers. One reason is probably the fact that large numbers of 

 green organisms pass through the entire digestive tract of tadpoles 

 without harm. Not only Euglena and Phacus, but Trachelomonas, 

 Eudorina, desmids, filamentous algae, and such distinctly animal 

 forms as Dlfflugia, rotifers, and entomostracans emerge unharmed 

 from the gut of tadpoles, so that one is inclined to wonder what 

 may constitute the source of nutrition for them. Ordinary species 

 of Euglena and Phacus, when removed from the rectum and placed 

 in water or even in weak physiological salt solution, will put out a 

 flagellum and swim about. Having seen many cases of this kind, 

 it was with difficulty that the writer first convinced himself of the 

 entozoic habit of Euglcnamorpha. 



Alexeieff ('12) records the finding of numerous Euglena and 

 Phacus alive and moving in the intestines of tadpoles, and using 

 this fact with the known cases of parasitism among Euglenoids 

 12 



