636 Wisconsin Academy of Sciences , Arts, and Letters. 
era! centers of aggregation of the spirem as Strasburger believes 
should be the case in nuclei with several nucleoli. 
The coils of the second contraction figure extend toward the 
periphery of the nucleus in all directions making it very diffi¬ 
cult to determine whether any relation exists between the num¬ 
ber of coils and the number of chromosomes. If the transverse 
segmentation of the spirem takes place in the peripheral region 
of the nucleus the number of the chromosomes will equal the 
number of coils of the spirem. In the earlier diakinesis stages 
the presence of very short double chromosomes in the same 
nucleus with others of the same diameter but five or six times 
as long (Fig. 24) suggests the possibility of a later segmenta¬ 
tion of some of the first formed spirem segments, for if the un¬ 
equal lengths were due to a more rapid contraction of certain 
chromosomes we should naturally expect the shorter chromo¬ 
somes to have a greater diameter. There is however a decided 
decrease in the volume of the individual chromosomes following 
their formation by the breaking up of the second contraction 
figure so that the chromosomes of the equatorial plate and meta¬ 
phase are considerably smaller than those of early diakinesis. 
It is probable that this irregularity of the chromosomes of early 
diakinesis may be due to a more rapid decrease in volume as 
well as length in some chromosomes than in others. Polar 
views of the equatorial plate stage although showing a, certain 
diversity in the size of the chromosomes do not show any such 
great difference as is seen in earlier diakinesis (Figs. 29 and 
30). 
There is however a difference in the size* of the chromosomes 
as they appear in the equatorial plate stage. In polar views of 
the equatorial plate from five to seven chromosomes lying in the 
interior of the chromosome group are seen to be decidedly 
smaller than those lying around the periphery. There is also 
some irregularity in size among these peripheral chromosomes, 
one or more being usually larger than the rest. (Figs. 29 and 
30). Figure 30 shows 24 double chromosomes and figure 29 
shows 22. The former number is evidently the reduced number. 
The multipolar spindle is formed from a felted zone as has 
