8 General Morphology of the Protozoa 



Fig. 1. 4. A. Palmella stage, as seen in Haematococcus and related 

 Phytomonadida; diagrammatic (after Wollenweber). B. Gleocystis stage, as 

 found in various Chlamydomonadidae; diagrammatic (after Goroschan- 

 kin). C. Chain ("catenoid colony") of Haptophrya niichiganensis; x90 

 (after Bush). D. Chain formed in fission of Gonyaulax catenella; x580 

 (after Whedon and Kofoid). 



CORTEX, SECRETED COVERINGS, 

 AND SKELETONS 



No well developed cortex is apparent in simple flagellates or 

 typical amoebae. The superficial cytoplasmic layer of Amoeba proteus 

 is formed from, and gives rise to endoplasm continuously during amoe- 

 boid activity and thus lacks the relative permanence of the cortex in more 

 specialized Protozoa. However, some amoeboid organisms have a thin 

 pellicle similar to that of Amoeba verrucosa. In this species, the pellicle 

 maintains itself under mechanical stress in microdissection (96). 



At the other extreme, the relatively thick cortex of a ciliate may con- 

 tain basal granules, fibrils, myonemes, mitochondria, and other inclu- 

 sions, and sometimes trichocysts. Although often flexible, the layer is at 

 least firm enough to maintain a typical body form in the swimming 

 ciliate. The pellicle covering the surface of ciliates seems to be a distinct 



