1024 



PARASITES OF PROTOZOA 



is only speculation and is, in fact, improbable. Kahl stated that it 

 seemed to him inconceivable that this symbiosis is without advantage to 

 the host. 



Dogiel (1929) observed Sarcma-like bacterial epiphytes on Didesmis 

 ovalis. These formed a group of regularly quadrangular form, in definite 

 number and arrangement, and were located in a preferred place on the 

 body surface. Other epiphytes, regarded as being probably bacteria, were 



Figure 214. Characteristic bacteria adherent to the pellicle of Cy did turn from the 

 intestine of sea urchins. A, C. rhabdotectnin Powers; B, C. ozakii Yagiu; C, C. stercoris 

 Powers. (After Powers, 1935.) 



found on two species of Diplodinium. These had the form of an elongate 

 oval body, attached by a stalk to the pellicle. They were found also 

 free, ophryoscolecids being only an accidental substrate. 



Endobiotic Schizomycetes 



The relationship between Protozoa and bacteria that live in the cyto- 

 plasm or, less frequently, the nucleus, is closer than that of the surface 

 forms. The bacteria must obtain all their nutriment from the host, in 

 the body of which they multiply. The association is sometimes a con- 

 stant one, the host seldom, or never, being found without the customary 

 microorganisms. These are then probably not detrimental to the host, 



