2 BOTANICAL GAZETTE [JANUARY 
Professors JoHN M. CouLter and CHARLES J. CHAMBERLAIN, and 
I wish to express my sincere gratitude for their kind suggestions 
and criticism during the progress of the work. 
Description 
CHROMOSOMES IN TELOPHASE OF VEGETATIVE MITOSIS 
In order to make a detailed study of the behavior of the chromatin 
material throughout nuclear division, it is necessary to begin with 
the study at the earliest possible stage of division. To begin with the 
resting nucleus is not early enough, and so I have started at the 
telophase of the previous division. 
The nucleus in the vegetative tissue, whatever its location may be, 
presents similar features, so that the description can be applied to 
the process of nuclear division in any tissue, although the figures 
in the accompanying plate were drawn from vegetative mitosis in 
young fronds, previous to the formation of spore mother cells. 
The chromosomes in the equatorial plate in typical mitosis gen- 
erally appear homogeneous. They split longitudinally and the two 
sets of daughter chromosomes begin to pass toward the poles. The 
slender and straight daughter chromosomes always retain this form 
until they reach the poles, where they are drawn more closely together 
and become more or less parallel. They remain for a while aggre- 
gated thus, in contact with the surrounding cytoplasm. If the 
chromosomes in this state could be called a nuclear primordium, 
evidently the daughter nucleus in the telophase consists of chromatin 
only. Then the process of vacuolation begins as follows. 
The loosely aggregated chromosomes draw near together and 
come into closer contact; at the same time each gradually loses its 
hitherto compact structure and vacuolation occurs irregularly at 
different places ‘fig. 1). The set of daughter chromosomes is thus 
a mere aggregate of vacuolate chromosomes. The limits of the 
individual chromosomes are not difficult to trace. The vacuolation 
seems to mean that there is either a secretion of fluid from the chro- 
mosomes or a dissolution of portions of them into liquid; and the 
contact of this fluid with the surrounding cytoplasm may precipitate 
a membrane which will separate the products of the vacuolate chro- 
matin from the cytoplasm. The daughter nucleus formed in this 
