Nov., 1914.] 
Stamens of Smilax herbacea. 
365 
change the nucleous disappears. It is not possible to discover 
whether it was dissolved or disintegrated into smaller bodies and 
ejected into the cytoplasm. The cytoplasm at this stage has a 
very spongy appearance, but no micronucleoli were seen in it. 
In the mother star of the first division the chromosomes 
are attached to the spindle fibers near their free ends with the 
head of the loop extending outward as found by Schaffner in 
Lilium philadelphicum (11) and by Miss Hyde in Hyacinthus 
(3). There is a gradual shortening of the spindle fibers and at the 
same time the chromosomes uncoil and pull apart at the outer 
head of the loop or at the point where fusion took place during 
synapsis. From drawings of metakinesis it will be seen that 
the transverse splitting of the chromosomes of Smilax herbacea 
is not simultaneous as is found in many plants. (Fig. 27). After 
metakinesis the chromosomes are arranged around the poles 
forming the daughter stars of the first division. (Fig. 28). There 
is also a perceptible increase in the density of the cytoplasm in 
the equatorial region where in a short time a distinct cell plate 
is seen. By the time of the complete formation of the cell plate, 
the spindle is no longer visible and a new nuclear membrane 
is laid down around the daughter masses of chromatin material 
thus forming two new cells very similar to the parent cell, but 
much smaller. With the formation of the new nuclear membrane, 
it is also found that the nucleoli of the daughter cells are beginning 
to appear. The chromatin material in these daughter cells 
does not undergo such changes as were evident in the nuclei of 
the sporocyte, but the newly formed chromosomes are massed 
together not to form a continuous spirem, but an irregularly 
shaped mass in which the individual chromosomes may be 
distinguished. (Fig. 29). 
The daughter cells do not immediately separate, but may be 
seen still clinging together after the second division is well 
advanced. In the second division the chromosomes are attached 
to the spindle fibers in the equatorial plane by the head of the 
chromosome, having the free ends extending outward. (Fig. 30). 
The separation of the chromosomes at this division is along the 
longitudinal split. After the second metakinesis we find the 
two daughter stars with the distinct chromosomes (Fig. 31) 
which were readily counted in several preparations from the 
polar views. The number was found to be twelve. (Fig. 32). 
The cell plates of this division soon appear and a new nuclear 
membrane is evident in each daughter cell around the rather 
small chromosomes which become more or less crowded together 
and connected by fine connecting strands. All the tetrads 
appeared to be normal, there being no such irregularities found 
as shown by Fullmer in Hemerocallis and by Miss McAvoy in 
Fuchia. 
