728 Digby .— 77 /£ Somatic , Premeiotic , and 
between the premeiotic and meiotic divisions. The account of the somatic 
and premeiotic divisions will be followed by that of the meiotic phase. 
The methods used have been described in a previous communication 
( 3 ) and it is superfluous to repeat them here. 
I. Somatic and Premeiotic Divisions. 
One of the chief aims of this examination of the somatic divisions has 
been to ascertain the visible mode of transition from the telophase to the 
early prophase; that is, to follow the disorganization of the chromosomes 
and the gradual distribution of their substance throughout the nucleus, and 
to watch the ensuing reconcentration of their elements and their ultimate 
reorganization. In order the more clearly to demonstrate this demolition 
and reconstruction, the more usual plan of entering upon the cycle of 
nuclear division at the ‘ resting ’ stage has been abandoned for that of the 
metaphase; for at the metaphase one is confronted with tangible entities, 
whereas at the ‘ resting ’ stage one is dealing with a questionable and 
perhaps hypothetical structure. 
Metaphase. 
As the chromosomes go on to the spindle they may show every degree 
of longitudinal fission (Pl.LIX, Fig. 1). In some the split may have so far 
extended as to separate the daughter chromosomes widely ; whilst in others 
it is merely to be recognized as a bright line in the substance of the chromo¬ 
somes, and in others again it may be invisible, the chromosomes apparently 
being still homogeneous. This liomogenity is especially characteristic of 
the chromosomes of the archesporium, for in these nuclei the longitudinal 
fission is often not seen until the chromosomes are about to separate on the 
equatorial plate. This character may be accounted for by the relatively 
larger amount of chromatin-staining substance in those cells which are to 
give rise to the germ cells. On the other hand, in the nuclei of the roots 
the longitudinal fission is much more precocious, and may be seen in the 
early spireme (Figs. 8 and 9). The cells of the pericycle show exaggerated 
fission as compared to those of the inner tissues (Fig. 12). This is pro¬ 
bably due to the more rapid penetration of the fixing solution through the 
outer cells. 
The nucleolus is drawn up on to the spindle in the confusion of the 
chromosome movement. It is deeply staining like the chromosomes, but can 
be recognized by its circular form. When the chromosomes have arranged 
themselves on the equatorial plate, the nucleolus is pushed off the spindle, 
and often appears to be repelled by a chromosome (Fig. 1). It must 
finally fragment with amazing rapidity, as it is constantly to be seen when 
the chromosomes have but newly attached themselves to the fibres, but 
as they complete their equatorial arrangement, and as they separate and 
