Chapter 30 

 Subphylum 2 Ciliophora Doflein 



THE Ciliophora possess cilia which serve as cell-organs of loco- 

 motion. In Suctoria the cilia are present only during early devel- 

 opmental stages. The members of this subphylum possess a unique 

 organization not seen in the Plasmodroma; namely, except Proto- 

 ciliata, the Ciliophora contain two kinds of nuclei: the macronucleus 

 and the micronucleus. The former is large and massive, and controls 

 the metabolic activities of the organism, while the latter is minute 

 and usually vesicular or less compact, and is concerned with the 

 reproductive processes. Nutrition is holozoic or parasitic; holophytic 

 in Cyclotrichium meunieri (p. 565). Sexual reproduction is mainly 

 by conjugation, and asexual reproduction is by binary fission or 

 budding. The majority are free-living, but a number of parasitic 

 forms also occur. 



The Ciliophora are divided into two classes: 



Cilia present throughout trophic life Class 1 Ciliata 



Adult with tentacles; cilia only while young. . Class 2 Suctoria (p. 695) 



Class 1 Ciliata Perty 



The class CiHata includes Protozoa of various habitats and body 

 structures, though all possess cilia or cirri during the trophic stage. 

 They inhabit all sorts of fresh and salt water bodies by free-swim- 

 ming, creeping, or being attached to other objects; some are para- 

 sitic in other animals. Free-swimming forms are usually spherical 

 to elliptical, while the creeping forms are, as a rule, flattened or 

 compressed. 



The cilia are extremely fine, comparatively short, and as a rule 

 arranged in rows (p. 48). In some forms they diminish in number and 

 are replaced by cirri (p. 50). The cilia are primarily cell-organs of lo- 

 comotion, but secondarily through their movements bring the food 

 matter into the cytostome. Moreover, certain cilia appear to be tac- 

 tile organellae. The food of free-living ciliates consists of small plant 

 and animal organisms which ordinarily abound in the water; thus 

 their nutrition is holozoic. The ciliates vary in size from less than lOju 

 up to 2 mm. in large forms (as in an extended Spirostcmum or Sten- 

 tor). The cytoplasm is distinctly differentiated into the ectoplasm 

 and the endo plasm. The ectoplasm gives rise to the cilia and tricho- 

 cysts and is covered by a pellicle. The endoplasm contains nuclei. 



545 



