500 THE CYTOLOGY OF THE SUGARCANE 
Black Cheribon can no longer be considered as a kind of practicle 
importance, since the original sugarcane-kinds Black Cheribon, Bat- 
jan, White Manilla, Red German New-Guinea at the present time occu- 
py much less than 1 % of the total surface of the sugarcane-planta- 
tions of Europeans, so that these kinds are now hardly ever cultiva- 
ted +). 
In connection with the fact, that Loethers is probably the father of 
100 POJ, we add to this part, the investigation of the Koesoemo-cane, 
which has been obtained by Mr. C. E. SELLEGER in 1899 on Tandjoeng- 
sarie from the cross Djamprok-cane 2 x Loethers 3. After a certain 
amount of extension, around 1901, Loethers-cane however, has also en- 
tirely disappeared from cultivation. 
Furthermore the investigation of two seedlings of 100 POJ occurs in 
this article, in connection with the possibility that 100 POJ may be 
one of the parents of EK 28. 
THE PARENT KINDS 
Black Cheribon. It was shown in the first part that the reduction 
division in the pollenmothercells of Saccharum officinarium frequently 
takes place in an irregular manner. This irregular reductiondivision was 
there described in detail in the case of Green German New-Guinea. 
Let us here resume the most important peculiarities of this division, 
as it is almost always also found in the case of Black Cheribon. In the 
prophase of the division of the pollen-mothercells the pairing of an in- 
determinate number of chromosomes sets out; or, possibly, these 
chromosomes have paired temporarily, but afterwards this pairing got 
lost. Consequently we find in the diakinesis-nuclei besides gemini a 
number of unpaired chromosomes, which, usually, are arranged in sets 
of two, frequently parallel with one another. In the metaphase both 
univalent and bivalent chromosomes occur in the nuclear plates, the 
univalent ones usually on the circumference, often not quite in the 
plane of the aequator. During anaphase, the chromosomes derived from 
') J. VAN HARREVELD. Statistiek van de verbreiding en de productie der riet- 
soorten in de oogst 1922. Archief voor de suikerindustrie in Ned.-Indié, Jaargang 
1923, III p. 241. 
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