PARASITES OF PROTOZOA 1089 



successive stages of penetration were studied in preparations. The authors 

 found no evidence that the parasite pushed an extensible pellicle before 

 it, forming an invaginated chamber in which it dwelt, such as was 

 described by Balbiani (I860) and Biitschli (1876) in Sphaerophrya. 

 Endosphaera was observed in cysts of Ophthonecta, which could account 

 for the survival of the parasite under unfavorable conditions. 



The embryos of E. multifilns Gonnert have five bands of cilia. Gonnert 

 (1935) observed penetration into Lenmeophrya, preceded by the re- 

 sorption of cilia and the development of a long, mobile, penetrating 

 protoplasmic process. He observed no canal connecting the internal 

 parasite to the surface of the host. Endosphaera lives, he stated, four or 

 five days, and an embryo may be produced every half hour. 



Sphaerophrya and Endosphaera appear to be relatively benign para- 

 sites, except when present in large numbers. The efi^ect is then evidently 

 mechanical. Balbiani (I860) remarked that oxytrichids with more than 

 fifty parasites were greatly swollen and deformed, but that ordinarily the 

 host seemed to be not at all inconvenienced. Gonnert found that Endo- 

 sphaera, when present singly, had slight effect on the host, but that the 

 host often perished from multiple infection. 



The Genus Amoebophrya Koeppen 



Amoebophrya is even more of a zoological enigma than is Stkho- 

 lonche, one of its hosts, which Korotneff (1891) wrote of as a "zoologi- 

 cal paradox." A modern study of the structure and development of the 

 organism, which would throw light on its affinities, is much to be desired. 

 The evidence that it is a suctorian, accepted by Koeppen (1894), Bor- 

 gert (1897), Sand (1899), and Hartog (1909, Cambridge Natural 

 History), is not convincing. Its assignment to the Mesozoa, made by 

 Korotneff (1891) and Neresheimer (1904, 1908, and later) and agreed 

 to by Collin (1912), does little more than emphasize its enigmatic 

 qualities. 



Hertwig (1879) described what he regarded as a very peculiar nuclear 

 form within the central capsule of three species of acanthometrid Radio- 

 laria. (Fig. 226D). He stated that he found this body twice in Acantho- 

 staurus purpurascens and once each in Acanthometra serrata and A. 

 claparedei; and he showed what is doubtless the same thing in Amphi- 

 lonche helonoides. He described this as a large vesicle contaming a very 



