1S1*5] Sirezfi: Kinetonnclriis of FlngeUatrs 191 



Nor can I agree with Calkins (1909) when he states that Sehaudinu 

 has "correctly compared it (chromidia) with the mieronuclei of the 

 Infusoria."' The two structures seem to be fundamentally and mor- 

 phologically different, as well as varying greatly in their behavior. 



In an earlier memoir (1895), Schaudinn discusses reproduction in 

 the Foraminifera Patellina corrugata and Discorbina globularis. In 

 all the specimens he observed there was but one nucleus in the early 

 stages. As the reproductive phase comes on, the nucleus becomes seg- 

 regated into a number of parts, visually seven or ten, scattered through 

 the cytoplasm. Some of these may later subdivide in the same way 

 until as many as thirty nuclei may be present. The protoplasm be- 

 comes divided up about these nuclei, forming new individuals which 

 escape from the parent body. In this case also the original nucleus is 

 considered the vegetative, and the parts into which it becomes divided 

 the generative, chromidia or nucleus. There is no indication in this 

 process of a nuclear dimorphism, though that is claimed for it. 



It is comparable with the successive divisions of the nucleus found 

 occurring in Amoeba, Trichomonas, etc., by which multinucleated indi- 

 viduals are formed in the process of multiple fission. 



Swarczewsky (1909, pi. 19, figs. 13, 14, 35-39) describes a process 

 in the formation of gametes in Allogromia ovoidea comparable to that 

 given by Schaudinn. The nucleus casts out its chromatin until only 

 the reticulate structure remains, which then gradually disappears. 

 These chromatin particles wander out to the periphery of the cell and 

 ultimately form the gametic nuclei. This is a case comparable with 

 the ones cited above, and also with other eases of chromidia formation 

 claimed by Schaudinn, Goldschmidt, and Hartmann as examples of 

 nuclear dualism. Swarczewsky, however, points out the fact that it 

 cannot be so interpreted in Allogromia ovoidea. since one mass of 

 chromatin performs both functions in the cell, first in its position in 

 the definitive nucleus, and second, by wandering out into the cyto- 

 plasm. 



The interpretation which Schaudinn has put upon these and 

 similar phenomena is open to certain cogent objections. In the first 

 place, he claims the chromidia in the cytoplasm as sexual or genera- 

 tive chromatin, forming the generative nucleus. The original nucleus 

 is formed of vegetative chromatin and is the vegetative nucleus, ac- 

 cording to his interpretation. A change of position and form is here, 

 apparently, the only real distinction between the two types of chro- 

 matin. Trophochromatin and generative chromatin can be distin- 



