STUDIES OF NON-PARASITIC PROTOZOA 13 



amoeba akin to this undegenerated free-living form in certain phases 

 from a suctorian. The slender lobopodia only lack the terminal 

 knob to be indistinguishable from the tentacle of a typical suctorian, 

 and though the nuclear structures differ from a typical suctorian, 

 a distributed nucleus may occur in ciliata, as, for instance, in 

 Trachelocerca. 



Comparison may be made between the ambulatory forms 

 (Fig. 2 ; 1a and 76 ; and 5 a and 56), with their multiple minute nuclei 

 and protozoa, in the chromidial state. It is easy to imagine a 

 minute chromidial amoeba behaving exactly as do the Guarnieri 

 bodies in the vaccinated cornea. 



Large associations of amoebae in fusion-masses (plasmodium 

 formation or plastogamy) would account for such appearances as the 

 colloid-like contents of the cysts in cystic ureteritis, and multitudes 

 of detached flagella of the gametes might be seen only when stained in 

 some particular way, and thus simulate slender bacteria or, if curved, 

 spirilla. In this way a disease might be thought to be caused by 

 bacteria when the very bodies on which the opinion was based were 

 but one of many phases of a protozoon, the real cause of the disease. 

 It would be easy to mistake forms such as 2, 3, and 4, or P, 10, and 

 77, for leucocytes. 



The forms breaking up into minute subdivisions, each with its 

 own tiny nucleus, might be explained as ' chromatinorrhexis,' or 

 some other process of disintegration. In addition to this, the 

 involution-forms and dead parasites would probably be considered 

 to be degenerated and necrosed elements of the host's tissues. 



Notes on Ciliates Colpoda Ciicullus. 



Among the ciliates one subclass, the Suctoria, are especially prone 

 to assume parasitic habits ; thus, from their being provided at a certain 

 stage with knobbed tentacles, like those of suctorians, I came to the 



