1g11] LUTMAN—CLOSTERIUM 407 
apparently gives rise to part of the chromosomes, the remainder 
coming from extra-nucleolar granules. In these opinions it will 
be seen that she agrees with the results of VAN WISSELINGH (43) 
on Spirogyra. At no time did she find a spireme formed. In the 
telophase, part of the chromosomes, the number apparently not 
having been determined, fuse to form this central body (nucleolus), 
while the remaining ones are distributed throughout the nuclear 
cavity as granules. 
Escoyrz (12) has also recently studied Zygnema in GREGOIRE’S 
laboratory, and has arrived at quite different conclusions from those 
of Miss Merrm™mAN. While the nucleolus is very large, the nuclear 
reticulum furnishes all the chromosomes. He does not deny the 
fact that the nucleolus may supply some of the chromatic material, 
but is certain that the morphological chromosomes do not come from 
it. He finds the chromosomes to arise, not by the fusion of granules 
as Miss MERRIMAN describes, but in the form of slender rods. In 
the telophase, the nucleolus is not formed by the union of the 
chromosomes at the center, but appears to arise independent of 
the chromatic reticulum. 
The spindle in Spirogyra is believed by STRASBURGER (39), 
MirzKewitcu (31), VAN WISSELINGH (44), and Bercus (2) to be 
purely of cytoplasmic origin, while MEUNIER (30) thinks it to be 
partly so. On the other hand, Fremminc (16) believed it to be 
derived from the nucleus itself. Miss MERRIMAN (29) seems to 
favor the view that the spindle arises intranuclearly in Zygnema. 
Escoyez (12) believes that in Zygnema it is formed from the 
cytoplasm, although he has not followed the process in detail. 
e very peculiar bodies, nucleolus or some structure correspond- 
ing to it, that are present in the resting nucleus of Closterium, I 
have described in my previous paper (27). On account of the 
importance of the question as to the behavior of these bodies in 
nuclear division, especially with reference to the theories of inherit- 
ance, which makes the chromatin or the chromosomes the special 
idioplasm, it will be well to notice some of the recent opinions 
relating to the réle of the nucleolus in the formation of the chromo- 
Somes, especially in the higher plants. 
WaGER (45) has recently quite thoroughly reviewed the litera- 
