206 POLLINATION AND CROSS-FERTILIZATION IN THE JXTAR PLANT 



ill a compact type of panicle. Tliartliur taken in the same way gave 20% or 

 1G5 plants out of 828. BalU puts the highest number at 50%. 



Examination of Crosses. 

 Grain characters. The colour of the grain is either red, white, ot yello^v. 

 The red grains owe their colour to the presence of a red coloured cell sap in the 

 cells of the pericarp. This colouring extends also to other parts of the plants 

 particularly to the leaves. During the vegetative period the red colour is 

 masked by the chlorophyll, but when the plants ripened the leaves of the red 

 grained plants stand out on account of the red colouring matter contained in 

 the leaves. The yellow colour is similarly due to a yellow coloured cell sap 

 in the cells of the pericarp. The colour likewise extends to the foliage of the 

 plant but at the time of ripening is less noticeable, the darker yellow leaves 

 of the yellow grained plants being liable to be overlooked by a casual observer. 

 The leaves of the white grained plants at harvest are straw coloured. 

 The colour of the plant can be detected at the time of flowering, the 

 stamens and stigmas of the red grained plants being orange, and those of the 

 yellow and white pale yellow. 



Cross I.2 

 In the first natural cross observed, namely, Lai Juar, 1908, the head^sent 

 in may be taken for our purpose as an Fi plant, heterozygous with regard to 

 the colour of the grain containing a simple pair of allelomorphs, presence and 

 absence of red. The number of plants was unfortunately small, but the 

 numbers indicated that this cross conformed to the Mendelian interpretation. 



Cross II. 

 In tJ)e same yeai Shenaliwani D proved to be a heterozygous plant for the 

 same pair of characters. 



Cross III. 

 In 1910 Lai Guranj, which had been true to the red character of the giaii\ 

 in the single plant cultures, began to split into red and white. This was 

 evidently a case of natural cross-pollination in the single plant cultures, the 

 hybrid being heterozygous for the same pair of allelomorphs. 



\ Ball, C. R. Loc. ciL, p. 283. 



2 'the crosses dealt with in this paper were left unprotected. The reasons for doing so were : 

 first, that the majority of the observations were confined to crosses in the compact type of panicle 

 and the lax type with long glumes in both of which tlie percentage of natural cross-pollination 

 is extremely low ; and second, tliat the characters under consideration are well marked and the 

 small amount of crossing which occurred was immediately detected. 



