THE CYTOLOGY OF THE SUGARCANE 525 
vorable shortly before flowering, serious disturbances in the metabo- 
lism of the sporogenous cells will not occur, thus favoring a much grea- 
ter fertility. 
This is the reason why the Experimentstation has now chosen a 
garden for experiments on hybridisation, which is situated in a mois- 
ter and cooler climate than that of Pasoeroean, a measure which will 
doubtless favor those experiments. 
CONCLUSIONS 
The cultivated kinds SW 3, SW rrrand DI 52 possess 40 chro- 
mosomes in the haploid, 80 in the diploid phase. The parents of these 
kinds, Black Cheribon and Batjan, both varieties of Saccharum offici- 
narum, also have 40 chromosomes in the haploid phase. 
100 POJ possesses 89 chromosomes. Loethers cane which differs from 
S. officinarum has 98 or 99 chromosomes in the diploid phase. The sus- 
picion, that Loethers might be the father of roo POJ is much streng- 
thened by the numbers of chromosomes found; the number 89 of 100 
POJ equals namely that of the sum of the haploid chromosomes 40 of 
Bandjermasin hitam and 49 of Loethers. 
In the case of Koesoemo, a cross of Djamprok x Loethers, 93 chromo- 
somes occur, a number distinctly differing from 80, the latter being the 
chromosome number of the seedlings obtained from crosses of varie- 
ties of Saccharum officinarum with one another. 
EK 2 possesses 40 chromosomes in the haploid phase. Cytology is 
unable to settle whether Lahaina or Bandjermasin hitam has been the 
mother of EK 2, because each of these have 40 chromosomes in the 
haploid phase. 
EK 28 possesses 80 chromosomes in the diploid phase. The question 
whether this cane could be a descendant of zoo POJ, can not be ans- 
wered with certainty by cytological investigation. Yet the possibility 
can not be denied, as it seems, that zoo POJ can form eggcells with 
40 chromosomes, besides eggcells with some chromosomes more. 
| Probably there exists in the sugarcane a relation between regu- 
lar or irregular reduction division and fertility. Both are in all 
probability strongly influenced by unfavorable growthconditions of 
the cane. 
