1909] YAMANOUCHI—CUTLERIA AND AGLAOZONIA 381 
The cells in these regions are full of plastids, with usually a single 
nucleus in the center. The nucleus in the resting state is very small, 
generally about the size of the plastids or sometimes a little smaller. 
The network is so finely built that it is hard to recognize much 
chromatin in it. Neither centrosomes nor central bodies with or 
without radiations seem to be present. 
In early prophase the nucleus increases in size until it is twice the 
diameter of the resting nucleus and occupies a greater part of the cell, 
pushing aside the numerous plastids toward the periphery. During 
the growth of the nucleus, there appear just inside of the membrane 
chromatin knots which are evidently worked out from the chromatin 
network by the rearrangement of the material. These chromatin 
knots, which are of course in continuation with less deeply stained 
chromatin fibrils, are variable in number at first, but gradually there 
appears a certain number of chromatin knots that are afterward 
detached from the chromatin fibrils and become chromosomes, 
24 in number. The chromosomes after segmentation gradually 
assume a slightly elongated rod-form and become arranged at the 
equatorial plate. 
A little before the equatorial plate stage, two kinoplasmic accumu- 
lations arise from the cytoplasm surrounding the nuclear membrane 
at two poles. A well-marked central body in the kinoplasmic mass 
occurs only at late metaphase. The chromosomes split longitudinally 
and half of each chromosome proceeds to each pole. During this 
entire process the spindle is intranuclear. At telophase the nuclear 
membrane disappears and the two sets of daughter chromosomes, in 
a state of close aggregation, are now surrounded by cytoplasm, and 
the formation of the nuclear membrane follows. 
When the daughter nuclei are organized, the central spindle 
disappears completely. The cytoplasm lying between the two nuclei 
begins gradually to assume a coarse, irregular, alveolar structure, and 
the walls of the alveoli, probably after a change in their material, 
form a new cell plate. 
Thus vegetative mitosis agrees in its essentials in both male and 
female plants. 
FORMATION OF MALE GAMETES.—When the male plant is young, 
the surface of the thallus bears tufts of hairs here and there in some- 
