Nuclear Division in Funkia. 
391 
Text Fig. IV', V', Fig. 61. The great length of the chromosomes 
is very noticeable, also tlie extreme thinness of the products of di- 
vision: a differentiatiou into chromatin and linin is often quite clear. 
The chromosomes collect at opposite poles, and unite to form a 
network in which numerous aggregations of chromatin are still 
visible. These aggregation are unpaired, as are also the linin threads 
connecting them. Fig. 63 and 64 represent the nuclei of youug 
pollen grains, illustrating this fact. 
d) Behaviour of the nucleoli during the reduction di- 
vision. In the resting stage and early prophases of the pollen 
mother cells five or sometimes four nucleoli, all of which stain 
strongly with haematoxylin, are generally present. All except two 
usually disappear before synapsis, though a third is occasionally 
visible for some little time longer. No sign of fusion between the 
nucleoli was ever seen before synapsis, but they gradually diminish 
in size and become vacuolated. A number of threads from the nuclear 
reticulum often converge towards a nucleolus and it is sometimes 
difficult to distinguish a disappearing nucleolus from a large, single 
aggregation or knot of the reticulum. There seem to be no reaso- 
nable doubt that a darkly staining substauce is transferred from 
these nucleoli to the reticulum, which increases in staining capacity 
as the nucleoli diminish in size. Two large vacuolated nucleoli are 
eft in such a stage as is drawn in Figs. 18. 19. Fl. VIII. 
Miyake *) thinks that the number of the nucleoli is reduced from 
four or five to two by fusion, but I have failed to find any stages 
of union except in synapsis, when the two remaining nucleoli un- 
doubtedly fuse. No sickle shaped nucleoli, such as are so often 
described as occurring during the later stages of synapsis, were 
present in any of my preparations. 
The two large nucleoli are generally far apart during the early 
stages of synapsis but they approach later and one of them gradually 
decreases in size. Fusion is for a long time incomplete, the remains 
of the small nucleolus being found attached to the side of the larger 
one, like a »nucleolar« bud, all through the spireme stages and dur- 
ing Diakinesis (Figs. 37, 28, 43.). 
During the formation of the chromosomes one large round 
nucleolus only is found, the last remains of a small nucleolus being 
seen in Fig. 46. Fl. IX. The large one becomes more and more 
*) Miyake. 1906. p. 92. 
26 * 
