PROTOZOA AND OTHER ANIMALS 907 



the fresh-water oligochaete Chaetogaster diastrophus Gruith in the vicin- 

 ity of Bucharest infected by a euglenid parasite that they named Astasia 

 chaetogastris. The flagellates multiplied rapidly in the coelom, and the 

 infection was always fatal in from eight to thirteen days. When freed 

 into water, metabolic movement lessened and a flagellum developed. 

 Both forms had a stigma, and the free form as well as the parasitic one 

 was capable of division. This euglenid is more pathogenic than any 

 other described. One is reminded of the invasion of the hemocoele of 

 insect larvae by Glaucoma pyriforniis. 



Foulke ( 1884) wrote concerning the fresh-water sabellid Manayunkia 

 spechsa: "Several individuals of Manayiinkia were observed to be 

 preyed upon, while still living, by large monads, embedded in one or 

 more of the segments, which were sometimes excavated to a considerable 

 degree." It is possible that in this statement there is reference to a situa- 

 tion analogous to that of Astasia chaetogastris. 



Finally, in copepods, occurs Astasia mohilis, which was the first en- 

 dozoic euglenid to be observed (Rehberg, 1882). Alexeieff (1912) 

 studied it in Cyclops, finding it not only in the lumen of the intestine but 

 also twice in the eggs. It sometimes had a flagellum, and a stigma was 

 described. The metabolic activity and some features of the structure of 

 this organism have suggested to some sporozoan affinities. By Labbe 

 (1899), for example, it was included in the genus Monocystis. Alexeieff 

 discussed the possible euglenid origin of Sporozoa, and Stein (1848) 

 had long before remarked upon the apparent relationship between 

 euglenids and Monocystis. 



Jahn and McKibben (1937) studied a colorless, stigma-bearing 

 euglenid flagellate whose habitat is given as putrid leaf infusion. They 

 found the root of the flegellum to be bifurcated, as in Euglenidae; 

 whereas in Astasiidae, according to Hall and Jahn (1929), it is not 

 bifurcated. The new genus Khawkinea was established by Jahn and 

 McKibben for flagellates whose characteristics agree with those of 

 Euglena except that they are permanently colorless; and they assigned 

 to this genus not only their new species, K. halli, but also the free-living 

 form that had been known as Astasia ocellata Khawkine, A. captiva 

 Beauchamp, A. mobilis Alexeieff, A. chaetogastris Codreanu and Codre- 

 anu, and E. leucops Hall. 



In the question of the relationship of free-living and endozoic Pro- 



