AND SPECIES HYBRIDS WITHIN THE GENUS SACCHARUM 137 
mes lie in one mass at one of the poles and can no longer be separately 
distinguished. 
The diad is smaller than the one of S. spontaneum. 
In the homotype division the chromosomes lie so close together that 
an accurate count is impossible. 
Fig. 33 shows 3 pollen-tetrads of Ardjoeno. The two to the left which 
are still in connection with one another, a frequent feature in the case 
of Saccharum-tetrads, have been formed while the longitudinal axes 
were parallel to one another; in the case of those to the right these axes 
crossed one another. The first type is much more common than the se- 
cond one. It occurs but rarely that the axes cross one another under an 
acute angle. Tetrads like the ones pictured occur also among the other 
kinds of sugarcane of which I shall treat; they are distinctly smaller 
than those of glagah. 
The irregular reduction-division of Green German New-Guinea-cane. 
The irregularity consists in the fact, that during prophase the pairing 
of an arbitrary number of chromosomes sets out. Consequently we get 
in metaphase, besides gemini, unpaired chromosomes. During anapha- 

‘Fig. 34. 
Fig. 34. Diakinesis of Green German New Guinea x 2300. 
se the chromosomes derived from the gemini proceed regularly towards 
the poles, the unpaired chromosomes as a rule split longitudinally. The 
result is, that the nuclei- of the pollengrains probably obtain more than 
