626 PROCEEDINGS OF THE NATIONAL MUSEUM vol.87 



Chen and Stabler, 1935, found that the endamoebae parasitic in the 

 opalinids have a very wide geographical distribution. This is but an 

 abstract. See Chen and Stabler, 1936, for full publication. 



Stabler and Chen, 1936, described in some detail the endamoebae 

 parasitic in the opalinids. Trophozoites and cysts of Endamoeba 

 were described in detail, variations noted. The endamoebae seem to 

 produce no serious effect on the opalinids, as the latter swim actively 

 in the saline solution and undergo binary fission even though heavily 

 parasitized. The endamoebae in a species of Zelleriella from Chile 

 were found invaded by a Sphaerita-\ike organism. No specific 

 name was given to this Endamoeba, which closely resembles E. 

 ranarum. 



Chen and Stabler, 1936, found that the endamoebae parasitic in 

 the opalinids have a very wide geographical distribution, being found 

 in Egypt, China, Ceylon, the United States, Panama, Brazil, Uruguay, 

 and Chile. Different species belonging to all the four genera of the 

 family Opalinidae have been found parasitized by the amoebae. The 

 amoebae were also found in cysts of opalinids, thus constituting an 

 important method of transmission of amoebae from adult anurans 

 to tadpoles. 



Hegner, 1936, found that certain flagellates in the frog seem to live 

 longer than certain ciliates, after the host is dead. Oi)alina lived 

 for at least 4 days after the anuran host (frog) had died. 



Ivanic, 1936, described the mitosis in Opalina ranarum and in 0. 

 obtrigona. According to him the resting nucleus contains "plastin" 

 in one or more pieces. This "plastin" material may partly disappear 

 during mitosis and may be irregularly distributed to the daughter 

 nuclei. He believes [correctly] that there are no "macrocliromo- 

 somes" and "microchromosomes" but only one type of chromosomes 

 derived from the chromatin granules in the resting nucleus [no refer- 

 ence was made to the work of Pfitzner on Opalina ranarum in 1886 

 and to Tonniges' work on the same species in 1927]. 



Chatton and Brachon, 1936, on the basis of the arrangement and 

 fate of cilia lines of opalinids during division suggested that opalinids 

 are intermediate between the flagellates and ciliates. 



Chen, 1936a and b, gave a detailed account of mitosis in Zelleriella. 

 He reported that the behavior of chromosomes during mitosis is 

 essentially the same as that found in multicellular organisms. He 

 found, for the first time for opalmids, (1) that the chromosomes are 

 of different sizes and shapes and can be individually recognized; 

 (2) that there are two chromosomes of each size and shape, indicating 

 diploidy; (3) that the nucleoli are constantly associated with certain 

 portions of certain chromosomes: (a) Depending on the subspecies, 

 there may be 4 or 6 nucleoli formed respectively on 4 or 6 (2 or 3 

 pairs) of the 24 chromosomes; (6) the location of the nucleolus is 



