Gruber (Ber. Ges. Freib. 1888) has shown that in several marine Ciliata the meganucleus is represented by an enormous number of minute granules disseminated through the endosarc, which, on the approach of fission, unite into a single meganucleus. As an adjacent micronucleus makes its appearance at this stage, he infers that the micronucleus must be also resolved in the intermediate life of the cell into granules too small for recognition under the highest magnification attainable, and that they must then coalesce.
In the peculiar Peritrichan Spirochona the division of the meganucleus is a much more complex process than usual, and recalls that of the undifferentiated nuclei of many Rhizopods (see Rompel in Z. wiss. Zool. lviii. 1894, p. 618). Opalina has neither mouth nor anus, nor contractile vacuole, but a large number of similar nuclei, that divide by a true mitotic process, like micronuclei. We have referred it (pp. [114], [123]) to the Flagellates, next to the Trichonymphidae.
Save the Opalinopsidae, which are usually termed "Opalinidae"; but which cannot retain the latter name on the removal of the genus Opalina to the Flagellates.
Phil. Trans. clxxxv. 1895, pp. 355 f.
Arch. Zool. Exp. (2) vi. vii. 1888-1889.