246 BOTANICAL GAZETTE [APRIL 
amitosis, is certainly much more complicated than a mere mass divi- 
sion such as occurs in the latter process. In the division of the cen- 
tronucleus of Empusa, we have, as was seen, intranuclear centers 
of division, or centrosomes, which function as active agents in 
nuclear division. Centrosomes, when they do occur, are, on the 
other hand, supposed to take no essential part in amitotic division. 
In the dividing nuclei of Empusa, we have also, besides active cen- 
trosomes, an arrangement of the chromatin in radiating fibers 
comparable to chromosomes, and, further, a simple spindle-appara- 
atus. I should therefore separate the process in this form far from 
amitotic division, although still regarding it as an extremely sim- 
ple type of mitosis. 
In the division of the nucleus in Euglena, the resemblance of the 
phenomena to amitosis was regarded by KEUTEN as so striking that 
he called the process in this organism a simple intergradation 
tween direct and indirect division. In the case of Coccidium 
SCHAUDINN remarks that the division of the nuclei takes place by a 
“primitive mitosis.” Should ScHAUDINN be able to find, further, 
as is probably possible with improved fixation, the division-centers in 
his second kind of division, which occurs in the stages following the 
fertilization of the egg, he should come to the conclusion that he has 
here also not, as he concludes in his paper, a still simpler type than 
the first, but a primitive mitosis essentially like the first. For in 
the event of similar intranuclear division-centers occurring in both 
cases, he would have two types of division somewhat comparable to 
the two types mentioned above in Empusa, which, as we have seen, 
differ from each other only in the amount of nuclear sap present, 
and in the earlier constriction and elongation of the second type. 
In Empusa, Coccidium, and Amoeba, the absence of an arrange- 
ment of the chromatin during the prophases of nuclear division in an 
equatorial plate, attests the extreme simplicity of the mitotic process 
in these instances. The absence of this equatorial arrangement 
leaves us, in fact, unfortunately in doubt as to the manner of the equal 
distribution of the chromatin between the two daughter nuclei. If 
we accept, however, the commonly accepted doctrine that “the 
daughter nuclei receive precisely equivalent portions of chromatin 
from the mother nucleus”? (WILSON, :00, p. 70), we must conclude 
