100 PROTISTS AND DISEASE 



molluscum body when treated by the same chemical reagents. 

 He found that coccidia were altered in appearance, but not 

 the molluscum. His conclusion was that the molluscum 

 body could not be a Coccidium, but that within the opaque 

 colloid covering of the molluscum body there was concealed 

 a parasite. This same view was adopted later by von 

 Prowazek with the addition that he identified the parasite 

 with some alleged minute granules in the middle of the 

 body, and he made the name Chlamydozoa for the group to 

 which the molluscum body belongs. 



Now, seeing that except for a thin cortex the middle of 

 the body is like the rest, and that the parasites appear from 

 what follows to be most closely related to the genus Synchy- 

 trium, and so not protozoa at all. Prowazek's name is based 

 on misconception ; it is misleading, and should be replaced 

 by some more appropriate term. 



Plassomyxa contagiosa. This name I have made to 

 apply to the causal parasite of molluscum contagiosum, and 

 seeing that some of its phases are easily studied in the living 

 state, the behaviour of the organism in water-cultures must 

 be given in some detail although they have already been 

 considered to some extent in Part IV. 



Fortunately, the bodies characteristic of this disease in 

 the human subject when full-grown are relatively large, 

 Fig. 27, and firm of texture, and hence it is easy to watch 

 what happens to them when they are placed in surroundings 

 that make it possible for them to show that they are living 



