




THE CYTOLOGY OF THE SUGARCANE 501 
the gemini, first move towards the poles. The univalent ones lag behind 
in the aequator and undergo fission, the much smaller split chromo- 
somes subsequently moving towards the poles also. Because the univa- 
lent chromosomes behave in this division exactly in the same way as 
chromosomes do during somatic karyokinesis, a reduction takes place 
only in the case of those chromosomes which had formed gemini. As a 
result of this incomplete reduction-division, a number of chromosomes 
superior to the haploid number reaches the daughter 
cells. 
In Fig. | an anaphase of Black-Cheribon is pictured. In 
the aequatorial plane 7 univalent chromosomes are here 
seen which have just split; one univalent chromosome, 
also already clearly split, lies nearer to one of the poles. 
There are here consequently 8 univalent chromosomes g 
present, all of which have split and which are clearly 
smaller than the chromosomes at the poles, derived from 

Enten Je 
the gemini. ee A 
: A naphase o 
The number of univalent BROOKS in sau the heterotype 
mothercells of Black Cheribon is very different in different division of 
E À Black-Cheribon 
nuclei. Among a total of 60 observations but one anaphase seen from the 
was found in which no chromosomes had lagged behind. side x 2300. 
In the 59 other anaphases the number of such varied from 4 
to 34. 
The univalent chromosomes made the counting of the chromosomes 
a very difficult task. Anaphases only allowed a correct estimation. 
In some such cases 80 chromosomes were with certainty counted. 
Fig. 2 pictures an anaphase in which 628 
| Mu eee 
in each of the two groups, moving tow 2 en eee) 
e 2 
ards the poles, 36 chromosomes were 668 + one 009% 
present, while 8 chromosomes lagged Vite 
e e° 
behind in the aequator. Black Cheribon 
consequently has 80 chromosomes in 
the diploid phase. Anaphase of the heterotype divis- 
AN 7 tbachet t Elei „ien of Black-Cheribon, viewed from 
ot. only BRE cterOlype~ VISION ne of the poles x 2300. 
but the homotype one also of Black 
_Cheribon takes place in an irregular manner. During the metaphase 
of this division a few chromosomes were sometimes scen out- 
side of the aequator, occasionally even near the poles. Here also 
De, ZE 
