

THE CYTOLOGY OF THE SUGARCANE 518 
Doubtless Loethers is a cane of very pronounced hybrid nature, pro- 
bably ahybrid between Saccharum officinarum with an unknown cane 
with another chromosome- number. 
The cane-kinds SW 3 and SW 111 arisen from the cross of Black Che- 
ribon with Batjan — both parents having 40 chromosomes in the hap- 
loid phase — possess also 40 chromosomes in the haploid and 80 in the 
diploid phase. DI 52, derived from the same parents, has a diploid 
chromosomenumber closely approaching 80. As SW 3 and SW rrr have 
exactly 80 chromosomes, this number is probably the correct one of 
DI 52 also. 
EK 2 has 40 chromosomes in the haploid, 80 in the diploid phase. Of 
this cane Frdy is the father, while it is not known whether Bandjarma- 
sin hitam or Lahaina is the mother: In as much as both of these latter 
canes have 40 chromosomes, the parentage can not be determined by 
means of cytological investigation. 
100 POT possesses 89 chromosomes in the diploid phase, a number 
equalling the sum of the haploid chromosomenumbers 40 of Bandjer- 
masin hitam and 99 of Loether’s cane. The suspicion that Loethers has 
been the father of zoo POJ is therefore much strengthened by this cy- 
tological investigation. 
Koesoemo-cane derived from the cross Djamprok x Loethers has 93 
chromosomes in the diploid phase. Here also therefore, the chromo- 
some-number deviates distinctly from the hybrids between different 
kinds of Saccharum officinarum which possess 80 chromosomes. It is 
curious that Koesoemo contains 4 chromosomes more than zoo POJ. 
_ The possibitity exists “at Djamprok-cane — which is no longer known 
_to us — has had a little more than 40 chromosomes, but it appears to 
me more probable that these 4 chromosomes are derived from Loethers, 
because hybrids between species with different chromosome- numbers 
often form gametes with unequal numbers of chromosomes. It is there- 
fore not at all impossible that in the formation of zoo POJ a male nu- 
cleus of Loethers with 49 chromosomes took part, while Koesoemo arose 
by the fertilisation of an eggcell of Djamprok by a male Loethers- 
: -nucleus with 53 chromosomes. 

EK 28. A cytological investigation of this form was of Reet inte- 
rest because its origin was not with certainty known. One of the suppo- 
sitions was that EK 28 had arisen from the cross zoo POJ x EK 2. 
Now zoo POJ contains, as was stated above, not 80, but 89 chromoso- 
Genetica VI 33 
