402 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9, 
black-Staining little body is usually in evidence, which can hardly be 
other than the endonucleolus, which appears to outlast the nucleolus in 
most instances. There is no evidence, however, that this is a permanent 
structure which is being carried over into the daughter nuclei. It soon 
after disappears and probably suffers a dilatory but like fate with the 
nucleolus. 
The chromosome pairs are drawn to the center of the cell as the spindle 
becomes bipolar, and soon become arranged in a definite plate. The 
circle of four soon breaks into two pairs, so that there come to be seven 
pairs of chromosomes lying side by side in the equatorial region. The 
condition at this time is generally one of great regularity. Most of the 
pairs are still in the form of rings, and one could not imagine a more typical 
picture of metaphase. The appearance is especially striking after the 
univalent chromosomes begin to be pulled apart, and before they have 
actually separated (fig. 30). 
Anaphase and Telophase 
The spindle fibers usually attach themselves to the middle of the chro- 
mosomes, which are V-shaped as they pass to the poles (figs. 30, 31). Occa- 
sionally, however, chromosomes are fastened by their ends to the fibers, 
in which case they appear rod-shaped. During anaphase the chromosome 
do not split preparatory to the homoeotypic mitosis. They pass entire 
to the poles where they form a compact little cluster, one chromosome 
usually occupying the center of the group with the other six lying around 
it (fig. 32). About this little group there develops a small vacuole-like 
region, the outer boundary of which becomes the nuclear membrane. At 
the same time a few little threads are here and there thrown across from 
one chromosome to another, forming slight connections. 
Interkinesis 
The daughter nuclei, so constituted, grow rapidly. The individual 
chromosomes are thus enabled to separate more and more, and tend to 
take a parietal position. As the nucleus increases in size they become 
more irregular in outline, but always remain perfectly distinct and separate, 
being attached to each other only in the most meager way by a few scant 
threads (fig. 33). Nucleoli also begin to make their appearance at this 
time, appearing at first as minute, faintly staining globules, which gradually 
grow in size, never becoming large, however, or appearing to exercise any 
important function (figs. 33, 34). There are usually several of them in 
a nucleus, and they develop in contact with the chromosomes or with 
the chromatin threads. The fact that several of them appear synchronously 
in various parts of the nucleus, and that they seem to have such an intimate 
connection with the chromosomes, suggests that they arise de novo, and 
are not descended from previously existing bodies such as the endonucleolus. 
