AND SPECIES-HYBRIDS WITHIN THE GENUS SACCHARUM 309 
normal individuals from different sowings. It is therefore highly 1m- 
probable that all of these should behave, cytologically speaking, in 
another way than the other individuals of those sowings. One has to 
suppose therefore, that all or nearly all individuals of one cross will 
behave cytologically in a corresponding manner. As the seed of one 
inflorescence can produce many thousands of hybrid individuals, and 
the possibility, that in the case of thousands of EMC from one inflores- 
cence, the reduction-division should have failed to occur, must be abso- 
lutely rejected, the only possible assumption is that the reduction- 
division did occur. Moreover a preliminary investigation of three varie- 
tal hybrids of Saccharum officinarum has always given 40 as the ha- 
ploid number, and this is only possible in the case of normal reduction- 
division. 
_ The measuring of nuclei of PMC in diakinesis gave in the case of the 
species-hybrids G 101 and G 107 the following results: 
G 101 G 107 
average radius of 20 nuclei average radius of 25 nuclei 
te oe U r=. 820 
1° — 674 DANCE 
In the case of S. officinarium r? = 407 was found, in that of S. spon- 
tanvum: T° = 539. 
The proportion between the nuclei of S. officinarum, S. spontaneum 
and S. officinarum X S. spontaneum therefore is 41 : 54 : 67, while 
their chromosomenumbers are 40, 56 and (approximately) 68 respecti- 
vely. One therefore sees, that in the hybrids the increase of chromoso- 
menumber is accompanied by a pretty nearly proportionate increase 
of nuclear volume. 
Besides hybrid individuals of S. officinarum x S. spontaneum such 
between S. officinarum and Chunnee were admitted to the preliminary 
investigation. These individuals were 181 POJ, 213 POJ and 920 POJ. 
It seemed to me, that their chromosomenumber was approximately 62 
to 64. This would point to a diploid number of approximately 124 to 
128. If one adds the diploid chromosomenumbers 80 of S. officinarum 
to the haploid chromosomenumber of Chunnee, which is approxima- 
tely 46 to 48, one has exactly a diploid chromosomenumber of 126 to 
128; reduction would then produce gametes with 63 to 64 chromoso- 
mes. We therefore have perfect agreement with the behaviour of the 
hybrids of S. officinarum x S. sponianewm. One sees therefore, that I 
