SEGMENTATION AND DIFEERENTIATION OF CHROMOSOMES. 287 
Fig. 5 shows an anaphase^ such as Avould presinnably result 
from a metaphase like fig. 1. The irregular scattering of 
the cliromosomes corresponds Avith the probable absence of a 
definite equatorial plate mentioned above. There is no reason 
to suppose that this irregularity of gronping leads to aii 
unequal partition of the chromosomes to the daughter-nuclei. 
Figs. 6 and 7 represent metaphase chromosomes from 
somatic mitoses Avith long chromosomes. Fig. G is part of a 
nucleus immediately before the chromosomes are placed on 
the spindle. Many of them are completely split into daughter- 
chromosomes, and some of them show little or no transverse 
segmentation. In certain of them, however (a,h,c,d), this 
is A'ery apparent, and it is to be noticed that the point cf 
segmentation corresponds Avith the apex of the V. It is 
striking, too, that in some, especially d, the division occurs 
much nearer one entl than the other. It is true that in d the 
two short segments are a little affected by foreshortening, 
but this is not enough to account for more than a very small 
part of the difference iu length between the two limbs. 
Fig. 7 is a later stage in so far that the equatorinl phite is 
fullj' formed, but neA'ertheless the chromosomes are not so 
completely split as in fig. 0. The indication of transverse 
segmentation is so slight that the fact that it is represented 
by the apices of the V’s could not have been recognised 
Avithout the help of the other figures. 
A number of chromosomes from different mitoses in various 
somatic tissues of two larAun are collected into fig. 8. A 
comparison of these with the foregoing figures will suffice to 
show the general nature of the segmentation iu the somatic 
chromosomes. 
'I'he chief points to notice are : 
(1) The frequent A'ery complete separation of the tAvo 
portions by the transverse joint. This separation often .seems 
at first sight to iiiA'olve the Avhole chromosome, but closer 
inspection shows that it involves only the chromatin. Hoav- 
ever separate the two chromatic portions may be, they are 
always joined by a bridge of non-staining substance. This 
