AND SPECIES HYBRIDS WITHIN THE GENUS SACCHARUM 123 
into a spireme of long, thin, segmented threads, which lie, strongly ben- 
ded, chiefly adpressed to the wall of the nucleus, some of which howe- 
ver always lie across the nucleus. I could not succeed in the making of a 
satisfactory drawing of these very complicated spiremes. 
In the next stage — the diakinesis — the threads are shortened and 
arranged in pairs. How this pairing took place, could not be determi- 
ned. At the beginning the threads of a pair, each of which represents a - 
chromosome, are still so long and frequently so bended, that a count 
of the pairs is impossible as these are in part still forming an insoluble 
mess. Gradually the chromosomes of each pair or geminus shorten 
more and more and arrange themselves closer together. This shorte- 
ning-process goes so far that finally the gemini appear as small clumps 
to the observer, which are but little longer than broad, while the majo- 
rity of them still shows their double nature. In favorable cases these 
gemini can be counted with approximate exactness. Diakinesis-nuclei 
in which all chromatine-clements are clearly bivalent are rather rare. 
For this purpose the shortening of the chromosomes should not have 
proceeded too far and must have taken place in the different gemini 
pretty nearly simultaneously. This happens but rarely; usually some 
gemini have shortened already too much, while others are still too long, 
which makes the count difficult. 
§ 2. The chromosome-number of Saccharum spontaneum L. 
The diakinesis-nuclei of Saccharum spontaneum (glagah) showan unu- 
sual large number of gemini; to wit 56. These gemini arrange themselves 
very regularly in the aequatorial plane while subsequently in the ana- 
phase the two chromosome-groups proceed regularly towards the poles. 
During the homotypical division also 56 chromosomes are, be it with 
difficulty, distinguishable in the two nuclear plates. By the aid of figu- 
res, this will now be elucidated. 
Fig. 12 gives a picture of a diakinesis-nucleus of S. spontaneum. In 
this nucleus the shortening of the gemini has taken place very regular- 
ly. All chromosome-elements clearly show their double origin. The 
gemini here have the shape of a X, an O or aV. We shall see later on 
that the same geminus-shapes are met with in S. officinarum. Many 
investigators have observed similar shapes in the case of other 
plants. 
