AND SPECIES-HYBRIDS WITHIN THE GENUS SACCHARUM 295 
Aegilops ovata were the same, notwithstanding Triticum should have 8 
and Aegilops 16 chromosomes. The chromosomes of Triticum however 
should be twice as large as those of Aegilops. For his measurements 
Barry choosed PMC in synapsis, which still touched one another, be- 
cause the central cavity had not yet been formed. Measurements of 
mine during the corresponding stages of S. officinarum and of S. spon- 
taneum, showed that the nuclei of the PMC of these species, were during 
this stage about of the same size. Measurements of diakinesis-nuclei 
gave the following results: 
S. officinarum Chunnee S. spontaneum 
G. D. N.G. Ardjoeno number of number of 
numb. o. observ. numb. of observ. observations observations 
25 25 . 29 30 
d = 1484u  d—148u 
d, = 14.82u d, = 16.14 dy = 16.28 
Ker IL DS Od Esher 0.14 
r3; = 406.9 1719246 25-9398 
The proportion of the nuclearvolumina of S. offixinarum, Chunnee 
and S. spontaneum therefore is 41 : 52 : 94. 
The nuclear volumina of S. officinarum and S. spontaneum in diaki- 
nesis therefore are approximately proportionate to the chromosome- 
numbers of the species e. g. 40 and 56. 
The Chunnee-cane which possesses in the haploid phase approxima- 
tely 46 chromosomes deviates in this respect rather considerably. 
C. A. BARBER !) is of opinion, that the Saccharum-varieties which 
produce sugar in British India, to which Chunnee and Ruckree belong, 
have arisen during a long period of mutation from Saccharum spon- 
taneum. He considers these forms to be varieties of the species Saccha- 
rum officinarum He writes: 
Saccharum spontaneum is the only species in the genus, which has 
close botanical relations with the sugarcane, which is named botani- 
cally Saccharum officinarum’’. He considers it probable that the thick 
tropical sugarcane-varieties are descendants of another, related, spe- 
cies which no longer occurs in the wild state. Still he counts with the 
possibility that these also may have arisen from S. spontaneum. Of 
this he writes: 
1) C. A. BARBER. The origin of the Sugarcane. International Sugar Journal. 
Vol. XXII. 1920, p. 249. 
