﻿igo3] BEHAVIOR OF THE CHROMOSOMES 257 



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daughter segments at the ends turned toward the poles may be 

 due to the manner in which the segments are attached to the 

 spindle, as both granddaughter segments are fastened to the 

 same bundle of fibers. 



As the pairs of granddaughter elements arrive at the poles, 

 they approach each other so closely that generally the identity 

 of the individual elements can not be recognized, but In many 

 cases the reconstruction of the daughter spirem can be followed 

 with precision. I have already shown how the free ends of the 

 daughter chromosomes unite to form a single daughter spirem, 

 [fiS^ ^^)- If the granddaughter segments form V's, the ends at 

 the angle fuse first, In case this has not already happened, and 

 then follows the fusion of the free ends. But in those cases in 

 which the granddaughter segments are U-shaped and closely 

 applied to each other side by side, it is evident that they must 

 first separate in order to unite end to end, for the spirem was 

 always found to be single. 



At first the spirem Is contracted, consisting of short turns, 

 but soon after the nuclear membrane is laid down, the spirem 

 becomes hollow and more regular and uniform. 



Gregoire ('99) states with emphasis that in Lilitim candidum 

 and Z. speciosiun especially the chromosomes maintain their 

 identity throughout in the daughter nucleus; that a continuous 

 spirem Is not formed but only a pseudo-spirem. My studies 



persica 



Martagon^ nothing 



.e fact that the 

 chromosomes do lose their identity In the daughter nucleus. 



The chromatin thread is not at all times an even and uniform 

 spirem. During the reconstruction of the daughter nucleus, the 

 chromosomes show a tendency to reticulate, becoming somewhat 

 lumpy, and the spirem, if we may so designate the chromatin at 

 this stage, is interrupted in many places. This is true especially 

 just after the spirem begins to become more hollow, and the 

 phenomenon may be regarded as a tendency to pass into the 



structure of the resting nucleus.' The tendency of the nucleus 

 to go into the resting stage is more pronounced in the embryo- 

 sac and in other plants to be mentioned in a later paragraph. 



