PARASITES OF PROTOZOA 1075 



the life cycle, are really parasites. The amoebulae were reported to take 

 on a helio2oa-like form on becoming free; Dangeard noted a similarity 

 to Nuclearia. An amoeboid parasite of Arcella was reported by Gruber 

 (1892), and evidently it is quite common, so many have been the ac- 

 counts of it. Doflein (Reichenow ed., 1927-29) and Deflandre (1928) 

 were inclined to accept the parasite interpretation of these supposed 

 reproductive bodies; but Cavallini (1926a, 1926b), without reference 

 to Dangeard's paper, reported in Arcella vulgaris and Centra pyxis 

 acideata division of the protoplasmic body into many small amoebae, 

 which leave the shell and develop into the mature testaceans. Never- 

 theless, it is probable that binary fission is, as Deflandre (1928) stated, 

 the only mode of reproduction that has been satisfactorily demonstrated 

 in Arcella. 



Penard (1912) found what he considered to be small parasitic 

 amoebae in Amoeba terricola and other species. They were often ob- 

 served moving actively within the pellicle of dead amoebae, from which 

 they eventually emerged and moved about freely, feeding on bacteria. 

 Penard found indication that these are parasites, the development of 

 which begins in the body of the large amoebae, but proof of this is 

 lacking. 



There is, to the writer's knowledge, only one record of amoebae 

 parasitic in a free-living ciliate. Chatton (1910) observed a very small 

 species living as a true parasite in Trichodina lahrorum from the rock- 

 fish. Opalinid ciliates are, however, not uncommonly parasitized. 



The hyperparasites of Opalinidae (Fig. 223 A) resemble E. ranarum 

 (Carini and Reichenow, 1935; Brumpt and Lavier, 1936; Stabler and 

 Chen, 1936). Those in difi^erent opalinids have not been found to show 

 any taxonomic distinctions; and the systematic name to be used, for 

 some forms at least, is Entamoeba paulista (Carini) ; to be used, that is, 

 if this amoeba is truly an independent species. Carini and Reichenow 

 were of the opinion that the hyperparasite is either identical with En- 

 tamoeba ranarum or is a race or species derived from this. Stabler and 

 Chen considered the question of the amoeba's synonymy with E. ranarum 

 to be still open. Brumpt and Lavier, though recognizing a probable dis- 

 tinction from E. ranarum, discussed the relationship as paraneoxenie, 

 in which an intestinal parasite of the amphibian attacks another parasite 

 that accompanies it, which then becomes a subhost. From the standpoint 



