278 A CYTOLOGICAL INVESTIGATION OF SOME SPECIES 
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Fig. 60. 
Fig. 60. Anaphase of the heterotype division in 247 B x 2300. 
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Fig. 61. 
Fig. 61. Anaphase of the heterotype division in 247 B x 2300. 
Abnormal division of the pollenmothercells in Green 
German New Guinea cane 
It has been pointed out already that it may happen in the case of 
G. D. N..G., that the pairing of chromosomes in the prophase of the 
division of the PMC fails almost completely. The result is an extremely 
abnormal division-process, during which normal chromosome-reduc- 
tion does not occur. Tetrads are formed which show all kinds of abnor- 
malities, and which contain often more than 4 cells. This was observed 
in preparations of 12 flowers all derived from one axis of a panicle 
which otherwise shewed normal division. In these flowers these abnor- 
mal divisions were very frequent; simultaneously transitions to nor- 
mal division and normal division itself were observed. Figure 62 shows 
a diakinesis-nucleus with pretty nearly all chromosomes in sets of two, 
which however do not combine to gemini. Frequently the chromosomes 
of one set are lying parallel to one another,which is particularly evident 
in the case of chromosomes visible when focussing at a high and at a 
low level. When focussing at a high level, a rather thick, somewhat 
O—O shaped chromosome is seen, which lies unpaired ; this is probably 
a geminus. The chromosomes lying at an intermediate level and which 
are drawn in the figure at the contour of the nucleus, are frequently so 
super-imposed that the picture can become unclear. Consequently the 

