1090 PARASITES OF PROTOZOA 



large nucleolus, around the sharpened end of which was a conical struc- 

 ture, the membrane of which was marked by circular striations. 



Fol (1883) found structures, which he described as analogous to 

 those seen by Hertwig, in the ectoplasm of Sticholonche zanclea. Some of 

 the Radiolaria contained spherical bodies, of rather complex structure, 

 which increased in size as the host became older, and contained an ill- 

 defined "spiral body." At maturity, these bodies left the host and were 

 capable of rapid movement, comparable to that of very active Infusoria. 

 The free organism had a spiral groove turning from left to right and 

 was completely covered with short, fine cilia. Other specimens of the 

 radiolarian contained a mass of globules, which increased in size 

 and number, finally becoming in volume equal to the rest of the body. 

 Fol advanced two hypotheses in interpretation of these structures: one, 

 that the globules are female reproductive elements, while the spiral 

 body is a sort of spermatophore; the other, which he regarded as also 

 reasonable, that the structures represent parasites. On the last supposition, 

 he stated, it would be difficult to explain the fact that the two kinds 

 of inclusions occur only in difi^erent individuals in approximately equal 

 numbers. 



Korotneff (1891), who studied the "spiral body" in Sticholonche 

 obtained at Villafranca, concluded that it is a parasite and made the 

 first suggestion as to its affinities. Believing himself to have demon- 

 strated an endoderm of a few cellular elements and a cellular ectoderm, 

 he considered the parasite to be closely related to the orthonectids and 

 possibly a stage in their development. 



The parasites in both Sticholonche and acanthometrids were studied 

 by Koeppen (1894), who gave them the names Amoebophrya sticho- 

 lonchae and A. acant hornet rae, and who was convinced that the organisms 

 are acinetids. He stated that he had studied all phases of development 

 in the same specimen. He based his taxonomic conclusion on supposed 

 development, in the parasitic phase, of an embryo, the spiral body, by 

 internal budding; and on the existence of tentacles for a short period 

 after this embryo became free and lost its cilia. The so-called tentacles 

 soon disappeared, and the body commenced to vary in form, showing 

 slow amoeboid movements. There is no proof that the protoplasmic 

 processes were actually tentacles; evidence is lacking that the behavior was 

 observed repeatedly under normal conditions; and there are no support- 

 ing illustrations. 



