218 



CH. ROUILLER, E. FAURE-FREMIET AND M. GAUCHERY 



Fig. 5. Fruntonia marina. Longitudinal section of some plia- 

 ryngeal proteic fibres (F). M, mitochondria. Magnification 

 X 34,000. 



By their structure and their position, these fibres are 

 readily comparable to those which form the pharyngeal 

 basket of Nassula. This fact should be remembered 

 if one wishes to study the comparative morphology 

 and evolution of the Ciliates. We have elsewhere 

 described similar fibres found around the buccal 

 infundibulum of the peritrichous Ciliates (5). 



From the cytological point of view, we see that 

 all the fibres examined are of proteic nature. 

 They are rigid and elastic, birefringent and built up 

 of elementary fibrils arranged to form a paracristal- 

 line structure. The elementary fibrils seem to be of a 

 fairly constant diameter, between 150 and 200 A. 

 Each of them must be considered as an already 

 complex macromolecular entirety. 



The elementary fibrils are always in a parallel 

 arrangement but their mutual ordering may be 

 either loose and irregular, or tight and regular in the 

 transverse plane with respect to a definite pattern. 

 In fact we have a system which we may name smecto- 

 nematic since the fibrils are arranged in a parallel 

 manner (as in the nematic mesomorphic states) but 

 in addition on a series of parallel planes (the latter 

 bringing to mind a smectic mesomorphic state). 



Unfortunately, there is some doubt as to the origin 

 of the fibres, that is to say their formation process, 

 their growth, their assemblage, their pattern-making. 

 The case of Frontonia indicates a possible relation- 

 ship with the ciliary rootlets similar to those previ- 

 ously described in Stentor (3). It is not sure whether 

 this is so with Nassula and Chlamydodon. 



Dysteria by the development of the pharyngeal tube 

 and the reduction of the protein rods to two large 

 stylets surmounted around the mouth by two com- 

 plex maxillae. 



It is known that in certain Hymenostomata a set of 

 pharyngeal fibres dip from the mouth into the endo- 

 plasm. In Frontonia marina (figs. 4 and 5) these long 

 and flexuous fibres appear on the same section, cut 

 in various planes, beside of trichocysts and mito- 

 chondria. Of a protein nature, they are here also 

 built up from a set of longitudinal homogeneous 

 fibrils, regularly spaced in series of parallel planes. 



References 



121-140 (1956) 



1. Corliss, J. O., System. Zool. 5, 68-91, 



and Arch. Prot. (1957, in press). 



2. Faure-Fremiet, E., Bull. soc. zool. France 75, 109-122 



(1950). 



3. Faure-Fremiet, E. and Rouiller, Ch., Compt. rend. acad. 



sci. 241, 678-680(1955). 



4. Faure-Fremiet, E., Rouiller, Ch., and Gauchery, M., 



/. Protozoal. (1957, in press). 



5. — Bull. soc. zool. France 81, 77-85 (1956). 



6. — Arch, d'anat. microscop. 45, 139-161 (1956). 



7. Rouiller, Ch., Faure-Fremiet, E., and Gauchery, M., 



Compt. rend. acad. sci. 242, 180-182 (1956). 



8. — /. Protozoal. 3, 188-193 (1956). 



9. — Exptl. Cell Research 11, 527-541 (1956). 



