AND SPECIES-HYBRIDS WITHIN THE GENUS SACCHARUM 319 
the univalent chromosomes are retained in multiples of 7, while such is 
not the case in roses which multiply sexually. 
The behaviour of the univalent chromosomes of Rosa, agrees in so 
far with that of those of Saccharum that here also, in the metaphase of 
the heterotype division, the univalent chromosomes lie at the circum- 
ference of the nuclear figure. The chromosomes of the gemini move nor- 
mally towards the poles, the univalent ones frequently lag behind and 
move subsequently, after longitudinal splitting, towards the poles. Fi- 
nally hetero-diploid hybrids in the genus Triticum have been investi- 
gated by Batty +) and KrHara ?). I shall not discuss the results of 
these investigations as there is no agreement whatever as to the number 
of chromosomes within the genus Triticum. R. OVERTON (1893) Go- 
LINSKI (1893), M. KOERNICKE (1896) and BALLY (1912) give 8 as the 
haploid number of Triticum vulgare. In the case of Triticum ovatum 
(= Aegilops ovata). BALLy found haploid 16 chromosomes. SAKAMU- 
RA (1918), to the contrary, gave 21 as the haploid chromosomenumber 
of Triticum vulgare, 42 as the diploid number, while, according to him, 
other Triticum — species possess 14, 28, and 42 chromosomes in the 
diploid phase. KIHARA agrees entirely with SAKAMURA in respect to 
these chromosomenumbers. 
We shall now proceed to those species-hybrids, which are tetraploid 
in the sporophyte and which arose from parents with equal diploid 
chromosomenumbers in the sporophyte. 
Miss DicBy 3) investigated cytologically a species hybrid of the genus 
Primula, the so called Primula kewensis. This species hybrid turned 
out to posses twice as many chromosomes as the parents. According 
to Miss DicBy this hybrid had arisen in the following way. In 1899 an 
aberrant form appeared in a sowing of P. floribunda as the result 
of a cross of P. floribunda with P. verticillata. This species-hybrid was 
intermediate between the parents and was named P. kewensts. In 
1) W. Barry. Die Godronschen Bastarde zwischen Aegilops- und Triticum- 
arten. Zschr. f. ind. Abst. u. Vererbungslehre. Bd. XX. 1919, p. 177. 
* H. Kruara. Ueber Cytologische Studien bei einigen Getreidearten. Mittei- 
lung I. The Botanical Magazine. XXXIII. 1919, p. 17. Mitt. III. Ueber die 
Schwankungen der Chromosomenzahl bei den Species bastarden der Triticum- 
arten. The Bot. Magazine XXXV. 1921, p. 19. 
3) L. DieBy. The Cytology of Primula Kewensis and of other related Primula 
hybrids. Annals of Botany. Vol. X XVI, p. 357. 
