PARNELL, AYYANGAR, RAMIAH, AND AYYANGAR 195 
some extraneous cause such as damage by insects or discolouration due to 
the grain coming in contact with water. It was found, however, that when 
such plants were carried forward they bred true to this character. The 
mottling is not seen till the grain is practically ripe; irregular light 
coloured areas then appear scattered over the grain and give it a distinctly 
moth-eaten appearance (Plate II, fig. 6). 
The inheritance of this character has not yet been worked out from crosses 
of the pure mottled types but, from the results of two Fy. families in which 
this type was present, it appears to be simply recessive to even-colouring. In 
the two families concerned six groups occurred, viz., dark, medium and 
ripening for both gold and furrows. In all groups both even and mottled 
occurred in about the same proportion, the total figures showing a 3: / ratio 
as below :— 
Even Mottled 
No. 2569. ree Olt 230 
42573) WP... se MOS 330, 
Total Sr Ee 1502 560 
Set ve bynliOl4 Boo 508 
Further work on crosses between pure types is necessary to confirm these 
results but, provisionally, an even-colouring factor EZ may be held responsible 
for the prevention of mottling. 
2. SHAPE OF GRAIN. 
One of the most striking features of cultivated rice is the enormous varia- 
tion shown by different varieties in the size and shape of the grain. There 
must bea large number of factors concerned in this variation and their 
analysis is likely to prove a matter of some difficulty. Generally speaking, 
as is very common in such cases, a cross between widely different types 
gives an F, somewhere intermediate and an F, comprising a complicated 
series of overlapping types that result in a more or less continuous variation 
between widely different extremes. 
In two cases, however, single-factor variations have been found. One of 
these, connected with a dwarf habit, is described later. The other, with which 
the present description is concerned, is closely connected with the factor G that 
has been dealt with above. 
It will be seen from Plate I that the ripening gold and ripening furrows 
types, figs. 1 and 4, are distinctly long and narrow, fine, compared with the 
dark gold and dark furrows types, figs. 2 and 5, that are shorter and broader, 
coarse. This distinction has been noted in all the varieties so far seen that 
show these colourings. In other words @ G@ varieties are coarse and 94 
