49 6 Farmer . — On Spore-Formation and 
portions, which only assume all the characters of chromatin 
when they meet in the nuclear framework. 
The regions in the linin which remain destitute of chromatin 
form the separation limits between the individual chromo- 
somes. The latter bodies, however, still remain united by 
these delicate filaments even when they begin to group them- 
selves under the nuclear wall. The chromosomes are also 
irregularly connected with each other by similar threads 
attached to other parts than the ends. 
The origin of the latter filaments is obscure, but I regard 
them as being of linin origin h They become later indistin- 
guishable from the threads of the achroma tic spindle, though it 
is not possible, as yet at any rate, to state definitely that they 
form any component structural elements in this body. The 
young chromosomes are at first of an irregular shape, but 
later they nearly always assume the form of the well-known 
bent rods, and on the appearance of the spindle they become 
attached in the equatorial plane at its periphery with the free 
ends directed outwardly from it. Each chromosome is now 
divided longitudinally by a split in the plane of the whole 
bent body. Nearly always the split is complete, and the two 
chromosome-halves then become ‘ roped up ’ so to speak along 
the spindle, in such a way that the apex of each V is directed 
towards the pole. In nearly every case a well-marked sheaf 
of fibres is attached to this apex and seems to pull the 
chromosome towards its destination. The two sister-halves 
are commonly connected across the equator, from which they 
are now diverging, by connecting fibres. The latter fibres 
become much more numerous as the chromosomes recede 
from each other, and a cell-plate is subsequently formed 
across them in the usual way. Very often some of the 
connecting fibres stray away from the main spindle and 
become attached to nucleolar-like granules, which are very 
1 It will be recollected that the linin exhibits frequent anastomoses, and possibly 
the structures in question may owe their origin to these ; at the same time it may 
be pointed out that young chromosomes often exhibit a ragged surface, even 
where anastomosis is not frequent. 
